Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 138
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-39476860

RESUMO

Changes in the ecosystems of vector-borne diseases can make the environment more or less favorable for mosquito vectors, animal reservoirs, and disease transmission. We report for the 1st time Anopheles marajoara in Argentina. In addition, An. deaneorum is reported for the 1st time in northwestern area of the country. Aedes fulvus, Culex eduardoi, Limatus durhamii, Mansonia pseudotitillans, Psorophora albigenu, Ps. cingulata, and Uranotaenia nataliae are recorded for the 1st time in Tucumán Province. Data on collection localities and comments about medical importance are also presented.

2.
Front Pharmacol ; 15: 1423719, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38994200

RESUMO

Background: Hypersensitivity to beta-lactam (BL) antibiotics is one of the most frequent reported drug allergies. In our population, it is common to find labels of BL allergy in electronic medical records (EMRs) that have not been assessed. The objective of our study was to detect patients with beta-lactam allergy labels in their EMRs and to assess how many of them are false after a correct diagnostic evaluation. Methods: A multicentre prospective study was performed with patients labelled as allergic to BLs in their EMRs in the previous 5 years. Demographical and clinical data, as well as variables regarding the BL allergy label and the characteristics of the index reaction from clinical history and EMRs, were recorded. Then, diagnostic assessments including clinical history, skin tests (STs), and drug provocation tests (DPTs) were conducted in order to confirm or exclude the diagnosis of BL allergy. Results: A total of 249 patients completed the study, of which 160 (64.3%) were women with a median age of 57 years (interquartile range [IQR], 45-68). The most frequent BL allergy labels detected were for penicillin (124), amoxicillin/clavulanic acid (61), and amoxicillin (54). Of the 204 patients who underwent STs, 20.1% were positive. DPTs were performed in 224 patients, showing good tolerance in 87.1% of cases. After the allergy diagnosis work-up, 186 patients (74.7%) were diagnosed as non-allergic to BL antibiotics. Conclusion: In our study population, the number of patients labelled as allergic to BLs in their EMRs was similar to that in previously published studies, with proportions near to 75%-80% being falsely labelled as allergic to BLs.

3.
Front Oral Health ; 5: 1408181, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39071245

RESUMO

Objectives: To test the biological properties of a novel non-restorative treatment method for arresting dentin caries based on silver nanoclusters (AgNCls) synthesized in polymethacrylic acid (PMAA). Methods: Synthesis of AgNCls was performed by photoreduction of AgNO3 in PMAA with 355 nm/wavelength light. AgNCls/PMAA was characterized by absorption/fluorescence spectroscopy and optical and atomic force microscopy. The stability of the clusters in an aerated PMAA solution was evaluated by means of fluorescence spectroscopy. Cytotoxicity was assessed using the MTT assay and antibacterial effect was determined for minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and colony forming (CFU) of Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus). 38% Silver Diammine Fluoride (SDF) was used for the control groups. Results: Chemical and structural identity of the clusters did not change within 9 months; Cell viability of 92%-89% was found after 24-48 h respectively. MIC and MBC were determined from 1:16 and 1:8 dilutions, respectively. Log CFU counts of S. mutans, and L. acidophilus treated with AgNCls/PMAA (3.4 ppm of silver) were significantly lower than in the control groups and even lower than when the same bacterial strains were treated with SDF (15,525 ppm of silver). Conclusions: AgNCls/PMAA presented chemical stability, acceptable cytotoxicity, and a potential antibacterial effect for strains associated with caries lesions at very low concentrations of silver.

4.
World Allergy Organ J ; 17(6): 100914, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38855082

RESUMO

Background: Drug provocation tests (DPT) are considered the gold standard procedure to ascertain the diagnosis of beta-lactam (BL) allergy. Regarding route of administration, current recommendations prioritize oral challenges, considering them safer, and reserving the intravenous route for drugs for which this is the only formulation. Objective: To compare in terms of tolerance and safety two protocols of BL DPT, using an oral protocol (OR-DPT) and an intravenous protocol (IV-DPT). Methods: A descriptive, retrospective study was performed, including adult patients who underwent IV-DPT or OR-DPT for suspected immediate or delayed hypersensitivity to BL antibiotics, over a period of 4 years (between January 2018 and December 2021). Demographical data, index hypersensivity reactions' characteristics and tolerance to DPT were reviewed. Results: A total of 1036 patients underwent DPT, mean age of 56.8 (standard deviation, SD, 17.8) years, 655 were women (63.2%). Immediate drug hypersensitivity reactions (DHR) had occurred in 564 of patients (54.4%). OR-DPT were performed in 439 (42.4%) and IV-DPT in 597 (57.6%). The frequency of reactions during DPT, regardless of the route used, was low (3.6%): only 16 (3.6%) in OR-DPT and 21 (3.5%) in IV-DPT. From IV-DPT, 16 out 21 DHR during DPT were immediate compared with 4 out of 16 in OR-DPT. Adjusted relative risk of developing a hypersensitivity reaction during IV-DPT versus OR-DPT was 1.13 (95% confidence interval (CI)0.57-2.22). Conclusion: The results suggest that OR-DPT and IV-DPT are both safe procedures when adequately performed. However, IV-DPT protocols showed a higher rate of immediate DHR during DPT probably due to the selection of basal high-risk patients to undergo IV-DPT. In conclusion, IV-DPT may be considered as an option for challenges in drug-allergy studies, entailing a precise administration.

5.
Nanotechnology ; 35(33)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38701760

RESUMO

For the first time, this study shows the nanoarchitectonic process to obtain an acetogenin-enriched nanosystem (AuNPs-Ac) using an aqueous extract fromAnnona cherimolaMill (ACM) composed of gold nanoparticles embedded in an organic matrix that acts as stabilizing agent and presents anti-inflammatory activity and cytotoxical effect against HepG2 cell line, promoting apoptosis. The synthesis of AuNPs-Ac was confirmed by x-ray diffraction analysis, showing metallic gold as the only phase, and the scanning transmission microscope showed an organic cap covering the AuNPs-Ac. Fourier-transformed infrared suggests that the organic cap comprises a combination of different annonaceous acetogenins, alkaloids, and phenols by the presence of bands corresponding to aromatic rings and hydroxyl groups. High-Performance Liquid Chromatography has demonstrated the presence of annonacin, a potent acetogenin, in the extract of ACM. Anin vitroanti-inflammatory activity of the extract of ACM and the AuNPs-Ac was performed using the albumin denaturation method, showing a nonlinear response, which is better than sodium diclofenac salt in a wide range of concentrations that goes from 200 to 400µg ml-1with both samples. The viability assay was studied using trypan blue, treating IMR90 and HepG2 at different concentrations of AuNPs-Ac. The results defined a median lethal dose of 800µg ml-1against HepG2 through apoptosis according to the ratio of caspase-cleaved 9/alpha-tubulin evaluated. It was also demonstrated that the nanosystem presents a higher cytotoxic effect on the HepG2 cell line than in IMR90, suggesting a targeted mechanism. In addition, the nanosystem performs better than using only the extract of ACM in the anti-inflammatory or antiproliferative test, attributed to their higher surface area.


Assuntos
Acetogeninas , Anti-Inflamatórios , Apoptose , Ouro , Nanopartículas Metálicas , Extratos Vegetais , Humanos , Acetogeninas/farmacologia , Acetogeninas/química , Células Hep G2 , Apoptose/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Nanopartículas Metálicas/química , Ouro/química , Ouro/farmacologia , Sobrevivência Celular/efeitos dos fármacos
6.
Community Dent Oral Epidemiol ; 52(4): 550-571, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38516782

RESUMO

OBJECTIVES: Dental behaviour support (DBS) describes all specific techniques practiced to support patients in their experience of professional oral healthcare. DBS is roughly synonymous with behaviour management, which is an outdated concept. There is no agreed terminology to specify the techniques used to support patients who receive dental care. This lack of specificity may lead to imprecision in describing, understanding, teaching, evaluating and implementing behaviour support techniques in dentistry. Therefore, this e-Delphi study aimed to develop a list of agreed labels and descriptions of DBS techniques used in dentistry and sort them according to underlying principles of behaviour. METHODS: Following a registered protocol, a modified e-Delphi study was applied over two rounds with a final consensus meeting. The threshold of consensus was set a priori at 75%. Agreed techniques were then categorized by four coders, according to behavioural learning theory, to sort techniques according to their mechanism of action. RESULTS: The panel (n = 35) agreed on 42 DBS techniques from a total of 63 candidate labels and descriptions. Complete agreement was achieved regarding all labels and descriptions, while agreement was not achieved regarding distinctiveness for 17 techniques. In exploring underlying principles of learning, it became clear that multiple and differing principles may apply depending on the specific context and procedure in which the technique may be applied. DISCUSSION: Experts agreed on what each DBS technique is, what label to use, and their description, but were less likely to agree on what distinguishes one technique from another. All techniques were describable but not comprehensively categorizable according to principles of learning. While objective consistency was not attained, greater clarity and consistency now exists. The resulting list of agreed terminology marks a significant foundation for future efforts towards understanding DBS techniques in research, education and clinical care.


Assuntos
Técnica Delphi , Terminologia como Assunto , Humanos , Consenso , Relações Dentista-Paciente , Assistência Odontológica/métodos
7.
Artigo em Português | LILACS | ID: biblio-1572927

RESUMO

Objetivo: Revisar a literatura a respeito da ocorrência de possíveis reações adversas e complicações decorrentes da utilização do ácido hialurônico para preenchimento labial. Revisão de literatura: As reações foram classificadas em imediatas ou precoces e tardias. Dentre as reações imediatas e precoces, foram encontrados eritema, dor, edema, hematoma, necrose, reações de hipersensibilidade, coloração azulada, processos infecciosos e presença de nódulos. As reações tardias foram descritas como granulomas e reações de corpo estranho, migração do material de preenchimento e cicatriz hipertrófica. Discussão: As reações adversas ao preenchimento labial acontecem devido às propriedades físico-químicas do material, falta de conhecimento anatômico e técnica inadequada. A maior parte das reações adversas podem ser diagnosticadas por meio de seus aspectos clínicos. No entanto, outros exames podem ser empregados, sendo a ultrassonografia é o método mais confiável para a investigação e identificação do agente de preenchimento. O tratamento, quando necessário, se baseia principalmente na injeção intralesional de corticoide ou hialuronidase. Conclusão: A identificação, formas de prevenção e intervenção precoce nas possíveis reações adversas são fundamentais para evitar o agravamento da complicação a longo prazo, além de aumentar a segurança na realização do preenchimento labial.


Aim: The aim of this study was to review the literature regarding the occurrence of possible adverse reactions and complications resulting from the use of hyaluronic acid for lip filling. Literature review: The reactions were classifiedas immediate or early and late. Among the immediate and early reactions, erythema, pain, edema, hematoma, necrosis, hypersensitivity reactions, bluish color, infectious processes and the presence of nodules were found. Late reactions have been described as granulomas and foreign body reactions, migration of filling material and hypertrophic scarring.Discussion: Adverse reactions to lip fillers occur due to the physical-chemical properties of the material, lack of anatomical knowledge and inadequate technique. Most adverse reactions can be diagnosed through their clinical aspects. However, other tests can be used, with ultrasound being the most reliable method for investigating and identifying the filling agent. Treatment, when necessary, is mainly based onintralesional injection of corticosteroids or hyaluronidase. Conclusion: The identification, forms of prevention and early intervention in possible adverse reactions are essential to avoid worsening the complication in the long term, in addition to increasing safety in the performance of lip filling.


Assuntos
Hialuronoglucosaminidase , Odontólogos , Edema , Eritema , Necrose
8.
FEBS Lett ; 598(3): 363-376, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38253842

RESUMO

Xylanases are of significant interest for biomass conversion technologies. Here, we investigated the allosteric regulation of xylan hydrolysis by the Bacillus subtilis GH11 endoxylanase. Molecular dynamics simulations (MDS) in the presence of xylobiose identified binding to the active site and two potential secondary binding sites (SBS) around surface residues Asn54 and Asn151. Arabinoxylan titration experiments with single cysteine mutants N54C and N151C labeled with the thiol-reactive fluorophore acrylodan or the ESR spin-label MTSSL validated the MDS results. Ligand binding at the SBS around Asn54 confirms previous reports, and analysis of the second SBS around N151C discovered in the present study includes residues Val98/Ala192/Ser155/His156. Understanding the regulation of xylanases contributes to efforts for industrial decarbonization and to establishing a sustainable energy matrix.


Assuntos
Bacillus subtilis , Simulação de Dinâmica Molecular , Bacillus subtilis/genética , Sítios de Ligação , Domínio Catalítico , Xilanos/metabolismo , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/metabolismo , Especificidade por Substrato
9.
J Phys Chem B ; 128(3): 635-647, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38227769

RESUMO

Enzymatic degradation of cellulosic biomass is a well-established route for the sustainable production of biofuels, chemicals, and materials. A strategy employed by nature and industry to achieve an efficient degradation of cellulose is that cellobiohydrolases (or exocellulases), such as Cel7A, work synergistically with endoglucanases, such as Cel7B, to achieve the complete degradation of cellulose. However, a complete mechanistic understanding of this exo-endo synergy is still lacking. Here, we used single-molecule fluorescence microscopy to quantify the binding kinetics of Cel7A on cellulose when it is acting alone on the cellulose fibrils and in the presence of its synergy partner, the endoglucanase Cel7B. To this end, we used a fluorescently tagged Cel7A and studied its binding in the presence of the unlabeled Cel7B. This provided the single-molecule data necessary for the estimation of the rate constants of association kON and dissociation kOFF of Cel7A for the substrate. We show that the presence of Cel7B does not impact the dissociation rate constant, kOFF. But, the association rate of Cel7A decreases by a factor of 2 when Cel7B is present at a molar proportion of 10:1. This ratio has previously been shown to lead to synergy. This decrease in association rate is observed in a wide range of total enzyme concentrations, from sub nM to µM concentrations. This decrease in kON is consistent with the formation of cellulase clusters recently observed by others using atomic force microscopy.


Assuntos
Celulase , Celulases , Trichoderma , Hidrólise , Celulose/química , Celulases/química , Celulase/metabolismo , Celulose 1,4-beta-Celobiosidase/metabolismo
10.
Sci Rep ; 13(1): 21126, 2023 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-38036660

RESUMO

The aims of this study were: To evaluate the surface hardness of simulated dentin caries lesions treated with either silver nanoclusters (AgNCls) synthesized in polymethacrylic acid (PMAA) or 38% silver diammine fluoride (SDF), as well as observe the penetration of the treatment solutions into the simulated caries lesions. Dentin blocks 4 mm thick obtained from caries-free third molars were sectioned and then simulated caries lesions on the occlusal dentin surfaces were created. Each specimen (n = 8) was divided into four sections: (A) treated with 20% AgNCls/PMAA; (B) treated with SDF 38% (FAgamin, Tedequim, Cordoba, Argentina); (C) sound tooth protected by nail-varnish during artificial caries generation (positive control); and (D) artificial caries lesion without surface treatment (negative control). AgNCls/PMAA or SDF were applied on the simulated lesions with a microbrush for 10 s, then excess removed. The surface hardness was measured by means of Vickers indentation test. To trace the depth of penetration, up to 400 µm, of silver ions, elemental composition of the samples was observed using EDX, coupled with SEM, and measured every 50 µm from the surface towards the pulp chamber. Laser Induced Breakdown Spectroscopy (LIBS) was also employed to trace silver ion penetration; the atomic silver line 328.06 nm was used with a 60 µm laser spot size to a depth of 240 µm. Student's-t test identified significant differences between treatment groups for each depth and the Bonferroni test was used for statistical analysis of all groups (p < 0.05). Mean surface hardness values obtained were 111.2 MPa, 72.3 MPa, 103.3 MPa and 50.5 MPa for groups A, B, C and D respectively. There was a significant difference between groups A and C compared with groups B and D, the group treated with AgNCls/PMAA achieved the highest surface hardness, similar or higher than the sound dentin control. A constant presence of silver was observed throughout the depth of the sample for group A, while group B showed a peak concentration of silver at the surface with a significant drop beyond 50 µm. The 20% AgNCls/PMAA solution applied to simulated dentin caries lesions achieved the recovery of surface hardness equivalent to sound dentin with the penetration of silver ions throughout the depth of the lesion.


Assuntos
Suscetibilidade à Cárie Dentária , Cárie Dentária , Humanos , Dureza , Dentina , Fluoretos Tópicos/farmacologia , Compostos de Amônio Quaternário/farmacologia , Compostos de Prata/farmacologia , Íons/farmacologia , Cárie Dentária/patologia
11.
Biomater Adv ; 153: 213561, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37515841

RESUMO

Carbon quantum dots (CQDs) are a new carbon-based nanomaterial that has attracted tremendous attention due to their excellent fluorescent properties, chemical stability, water solubility, and biocompatibility features. Here, fluorescent CQDs synthesized by a green nanoarchitectonic method using Cinchona Pubescens Vahl extract were evaluated as drug nanocarriers for carboplatin (CBP) delivery. The characterization methods showed CQDs with semispherical shapes and sizes around 5 nm, temperature- and pH-dependent functional groups that interact with the CBP molecule adding specificity to the drug-delivery system. Based on the load efficiency results, it seems that the CQDs can carry almost 100 µg of carboplatin for every 1 mg of CQDs. This is possible due to the self-assembly process that takes place through the interaction between the protonation/deprotonation functional groups of CQDs and the hydrolyzed CBP molecule. Through this process, it is created spherical nanoparticles with an average size of 77.44 nm. The CQDs-CBP nanoparticles release the drug through a diffusion-controlled release mechanism where the acidic media is preferred, and the EPR effect also plays a helpful role. Besides, the viability test shows that the CQDs have almost null cytotoxicity suggesting that they could be used as a promising cancer treatment, improving the efficiency of cell internalization and significantly increasing their drug delivery.


Assuntos
Cinchona , Neoplasias , Pontos Quânticos , Nanoestruturas/química , Cinchona/química , Carbono/química , Neoplasias/terapia , Humanos , Animais , Camundongos , Linhagem Celular , Sobrevivência Celular
12.
Glob Heart ; 18(1): 27, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37305068

RESUMO

Chagas disease (ChD) represents a significant health burden in endemic regions of Latin America and is increasingly being recognized as a global health issue. The cardiac involvement in ChD, known as Chagas cardiomyopathy (ChCM), is the most severe manifestation and a leading cause of heart failure and mortality in affected individuals. Echocardiography, a non-invasive imaging modality, plays a crucial role in the diagnosis, monitoring, and risk stratification of ChCM. This consensus recommendation aims to provide guidance on the appropriate use of echocardiography in ChD. An international panel of experts, including cardiologists, infectious disease specialists, and echocardiography specialists, convened to review the available evidence and provide practical recommendations based on their collective expertise. The consensus addresses key aspects related to echocardiography in ChD, including its role in the initial evaluation, serial monitoring, and risk assessment of patients. It emphasizes the importance of standardized echocardiographic protocols, including the assessment of left ventricular function, chamber dimensions, wall motion abnormalities, valvular involvement, and the presence of ventricular aneurysm. Additionally, the consensus discusses the utility of advanced echocardiographic techniques, such as strain imaging and 3D echocardiography, in assessing myocardial mechanics and ventricular remodeling.


Assuntos
Cardiomiopatia Chagásica , Doença de Chagas , Insuficiência Cardíaca , Humanos , Doença de Chagas/diagnóstico por imagem , Ecocardiografia , Cardiomiopatia Chagásica/diagnóstico por imagem , Consenso
13.
Mar Drugs ; 21(5)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37233491

RESUMO

In this work, the influence of the Sargassum natans I alga extract on the morphological characteristics of synthesized ZnO nanostructures, with potential biological and environmental applications, was evaluated. For this purpose, different ZnO geometries were synthesized by the co-precipitation method, using Sargassum natans I alga extract as stabilizing agent. Four extract volumes (5, 10, 20, and 50 mL) were evaluated to obtain the different nanostructures. Moreover, a sample by chemical synthesis, without the addition of extract, was prepared. The characterization of the ZnO samples was carried out by UV-Vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and scanning electron microscopy. The results showed that the Sargassum alga extract has a fundamental role in the stabilization process of the ZnO nanoparticles. In addition, it was shown that the increase in the Sargassum alga extract leads to preferential growth and arrangement, obtaining well-defined shaped particles. ZnO nanostructures demonstrated significant anti-inflammatory response by the in vitro egg albumin protein denaturation for biological purposes. Additionally, quantitative antibacterial analysis (AA) showed that the ZnO nanostructures synthesized with 10 and 20 mL of extract demonstrated high AA against Gram (+) S. aureus and moderate AA behavior against Gram (-) P. aeruginosa, depending on the ZnO arrangement induced by the Sargassum natans I alga extract and the nanoparticles' concentration (ca. 3200 µg/mL). Additionally, ZnO samples were evaluated as photocatalytic materials through the degradation of organic dyes. Complete degradation of both methyl violet and malachite green were achieved using the ZnO sample synthesized with 50 mL of extract. In all cases, the well-defined morphology of ZnO induced by the Sargassum natans I alga extract played a key role in the combined biological/environmental performance.


Assuntos
Nanopartículas Metálicas , Sargassum , Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas Metálicas/química , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Extratos Vegetais/farmacologia , Difração de Raios X , Testes de Sensibilidade Microbiana
14.
Sci Total Environ ; 886: 163922, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37164094

RESUMO

Global growth impacts on the increased use and demand for natural resources, requiring solutions for the high volume of industrial waste and by-products generated from the most diverse commercial areas, mainly the food sector. Among the main residues with a large volume generated, those from fruit processing, grain cleaning in processing units, vegetables, and discards from the animal production industry stood out. Approximately 1.3 billion all food produced worldwide is lost or wasted per year being fruits, vegetables, roots, and tubers responsible for about half of the total amount. Many of these by-products have interesting nutrients in their composition such as fibers, proteins, and bioactive compounds. An interesting example is the sugarcane bagasse. Fibrous residue, derived from sugarcane extraction, the bagasse represents about 30-34 % of the total sugarcane mass. This is one of the most abundant cellulosic residues and contains approximately 39 % of cellulose, 28 % of hemicellulose, and 18 % of lignin. Therefore, as well as the bagasse, several residues from agroindustrial can be considered promising alternative substrates, being valuable sources for the development of high-value-added products, such as biopolymers, bioenergy, and chemical products. In addition, the reuse of agroindustrial wastes may be considered an attractive option for reducing the environmental impact caused by their generation. In the case of biopolymers, the energy savings of bio-based polymers is around 20-50 GJ/t of polymer. In this review, we have selected two commercially promising approaches to the application and use of agroindustrial residues, aiming their use for biodegradable packaging and microbial polysaccharides bio-production, improving overall sustainability and economic aspects of the scientific research, technology and modern industry.


Assuntos
Celulose , Saccharum , Saccharum/metabolismo , Polissacarídeos/metabolismo , Lignina/metabolismo , Biopolímeros , Polímeros
15.
J. res. dent ; 11(1): 1-6, May 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1513028

RESUMO

The development of dental implants has revolutionized the rehabilitation possibilities for partially or totally edentulous patients. The long-term success of the dental implant depends on osseointegration and this is achieved by the combination of two essential stabilities: primary and secondary. Implant-supported prostheses are a great evolution for these treatments, positively interfering in the quality of life of the population, as they generate function and aesthetics for the patient. Thus, the present study aimed to radiographically evaluate complete dentures supported by an external hexagon conical implant in the anterior region of the mandible. More specifically, to evaluate the feasibility of using these implants in cortical bone of the mandible, to verify the success rate regarding the significance of peri-implant bone loss and to compare peri-implant bone loss between patients.

16.
Int J Mol Sci ; 24(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36674991

RESUMO

The present work shows the synthesis of ZnO nanoparticles through a green method, using sargassum extracts, which provide the reducing and stabilizing compounds. The conditions of the medium in which the reaction was carried out was evaluated, that is, magnetic stirring, ultrasound assisted, and resting condition. UV-Vis, FTIR spectroscopy, and X-ray diffraction results confirmed the synthesis of ZnO with nanometric crystal size. The scanning electron microscopy analysis showed that the morphology and size of the particles depends on the synthesis condition used. It obtained particles between 20 and 200 nm in the sample without agitation, while the samples with stirring and ultrasound were 80 nm and 100 nm, respectively. ZnO nanoparticles showed antibacterial activity against Gram-positive S. aureus and Gram-negative P. aeruginosa. A quantitative analysis was performed by varying the concentration of ZnO nanoparticles. In all cases, the antibacterial activity against Gram-positives was greater than against Gram-negatives. Ultrasound-assisted ZnO nanoparticles showed the highest activity, around 99% and 80% for S. aureus and P. aeruginosa, respectively. Similar results were obtained in the study of the anti-inflammatory activity of ZnO nanoparticles; the ultrasound-assisted sample exhibited the highest percentage (93%), even above that shown by diclofenac, which was used as a reference. Therefore, the ZnO nanoparticles synthesized with sargassum extracts have properties that can be used safely and efficiently in the field of biomedicine.


Assuntos
Nanopartículas Metálicas , Sargassum , Óxido de Zinco , Sargassum/química , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Nanopartículas Metálicas/química , Staphylococcus aureus , Antibacterianos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Testes de Sensibilidade Microbiana
17.
Restor Dent Endod ; 47(4): e43, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36518613

RESUMO

Objectives: This study compared the surface gloss (SG), gloss retention (GR), and color stability (CS) of 2 universal resin composites after chemical (CA) and mechanical (MA) aging. Materials and Methods: Twenty disc-shaped samples of G-ænial A´Chord (GC-Europe) and Filtek Universal (3M-ESPE) were polished with sequential abrasive papers. For CA, specimens were stored in 1 mL of 75% ethanol for 15 days at 37°C, and readings (SG, GR, and CS) were obtained at baseline and 5, 10, and 15 days. For MA, specimens were subjected to 10,750 simulated brushing cycles. SG and CS were evaluated after every 3,583 cycles. SG was measured with a glossmeter (geometrical configuration: 60°), and values were expressed in gloss units. Color was measured with a spectrophotometer using the CIE-L*a*b* color system. The Student's t-test, 1-way analysis of variance, and Scheffé test were used for statistical analysis (α = 0.05). Results: G-ænial presented significantly higher SG values than Filtek (p = 0.02), with GR reductions of 5.2% (CA) and 5.3% (MA) for G-ænial and 7.6% (CA) and 7.2% (MA) for Filtek. The aging protocol had no statistically significant effect on SG or GR (p = 0.25) from baseline to the final readings. G-ænial-MA presented the lowest color difference (∆E = 1.8), and G-ænial-CA and Filtek-CA had the largest changes (∆E = 8.6 and ∆E = 11.8, respectively). Conclusion: G-ænial presented higher SG values and better CS. Both restorative materials demonstrated acceptable GR and CS. Aging protocols impacted these properties negatively.

18.
Curr Opin Biotechnol ; 78: 102843, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36375405

RESUMO

The recent breakthrough in all-atom, protein structure prediction opens new avenues for a range of computational approaches in enzyme design. These new approaches could become instrumental for the development of technical biocatalysts, and hence our transition toward more sustainable industries. Here, we discuss one approach, which is well-known within inorganic catalysis, but essentially unexploited in biotechnology. Specifically, we review examples of linear free-energy relationships (LFERs) for enzyme reactions and discuss how LFERs and the associated Sabatier Principle may be implemented in algorithms that estimate kinetic parameters and enzyme performance based on model structures.


Assuntos
Biotecnologia , Engenharia de Proteínas , Biocatálise , Indústrias , Catálise , Enzimas/metabolismo
19.
Front Oral Health ; 3: 980048, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36389277

RESUMO

The aim of this systematic review was to update an existing review on the management of dental caries lesions in patients with disabilities so as to provide an up-to-date summary of the evidence. Randomized clinical trials and cohort studies related to preventive and restorative programmes for dental caries among people requiring special care, published in English, Spanish, Portuguese, French and German languages from February 1st 2011 to April 1st 2022, were retrieved from three databases ("updated review"). From the 1,105 titles identified using the search topic "Caries AND Disability", 17 papers informed in the analyses: 6 referring to caries preventive strategies and 11 related to restorative care strategies. Most of these studies targeted children and adults with intellectual/physical disability, although preventive and therapeutic strategies were also reported for frail older adults and onchohematological patients. Fluorides in tablets, gels or varnishes forms and the use of xylitol as a sugar substitute were reported as effective approach to prevent the onset of caries in high-risk groups. Minimally intervention treatment options such as the Hall technique, the ART approach and the use of SDF for arresting caries, were deemed suitable and effective strategies for treating existing lesions in-office. In conclusion, in the past decade (2011-2022) an increased number of articles reported strategies to prevent and manage caries among people requiring special care. Although an array of preventive and therapeutic strategies for dental caries exists, more and better-quality clinical evidence is needed to offer guidance to inform policy and practice for special care dentistry.

20.
Sci Rep ; 12(1): 15418, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104473

RESUMO

The aims of the study were: (1) To compare the staining effect on demineralized dentin simulating caries between silver nanoclusters (AgNCls) synthesized using polymethacrylic acid (PMAA) and silver diammine fluoride (SDF), and (2) to measure the shear bond strength (SBS) of a glass ionomer cement (GIC) to simulated caries lesions with and without the application of AgNCls/PMAA or SDF. Dentine blocks 4 mm thick from twenty-four non-carious third molars were sectioned and coated with nail varnish (Revlon, New York, USA). Simulated caries lesions on occlusal dentin surfaces were created (66 h in 0.05 M acetate buffer 2.2 mM calcium/phosphate pH 5.0). Specimens were divided into groups and treated with (n = 8): (A) 20% AgNCls/PMAA; (B) SDF 38% (Fagamin, Tedequim, Córdoba, Argentina); or (C) without treatment. AgNCls/PMAA or SDF were applied on the exposed surfaces with a microbrush for 10 s. Samples were incubated for 24 h at 37 °C at 100% relative humidity. Surface color was measured according to the CIE-L*a*b* system before and after demineralization (R0 and R1), 24 h and one week after treatment (R2 and R3), using a spectrophotometer (CM-600D Konica Minolta Sesing Inc., Japan). Groups A and B received an extra application of AgNCls/PMAA or SDF before a conventional GIC (Fuji IX-Gold Label, GC Corp, Tokyo, Japan) was bonded using a mold, 4 mm diameter × 3 mm high. For SBS, a Universal Testing Machine (Digimess RS-8000-5, China)-crosshead speed of 1 mm/min-was used. Statistical analysis was performed using ANOVA, Student-t and Scheffe-test at a significance of p < 0.05. Group A presented a stable color p = 0.24 between R1-R2 and R1-R3 in contrast to significant color changes in Group B (p = 0.02). SBS was higher (p < 0.01) in Group A (10.4 ± 2.7 MPa) compared to Groups B (3.3 ± 1.3 MPa) and C (4.0 ± 0.4 MPa), where no differences between the latter groups were observed (p = 0.77). Results of this preliminary study demonstrated that 20% AgNCls/PMAA did not stain simulated carious dentin and improved SBS of the GIC. The relevance of this study relies on the development of a therapeutic system to potentially arrest caries lesions without staining.


Assuntos
Suscetibilidade à Cárie Dentária , Dentina , Dentina/patologia , Fluoretos Tópicos , Humanos , Ácidos Polimetacrílicos , Compostos de Amônio Quaternário , Resistência ao Cisalhamento , Compostos de Prata
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA