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1.
An Acad Bras Cienc ; 96(2): e20231212, 2024.
Article de Anglais | MEDLINE | ID: mdl-38922279

RÉSUMÉ

The tumor microenvironment (TME) harbors several cell types, such as tumor cells, immune cells, and non-immune cells. These cells communicate through several mechanisms, such as cell-cell contact, cytokines, chemokines, and extracellular vesicles (EVs). Tumor-derived vesicles are known to have the ability to modulate the immune response. Monocytes are a subset of circulating innate immune cells and play a crucial role in immune surveillance, being recruited to tissues where they differentiate into macrophages. In the context of tumors, it has been observed that tumor cells can attract monocytes to the TME and induce their differentiation into tumor-associated macrophages with a pro-tumor phenotype. Tumor-derived EVs have emerged as essential structures mediating this process. Through the transfer of specific molecules and signaling factors, tumor-derived EVs can shape the phenotype and function of monocytes, inducing the expression of cytokines and molecules by these cells, thus modulating the TME towards an immunosuppressive environment.


Sujet(s)
Vésicules extracellulaires , Macrophages , Monocytes , Tumeurs , Microenvironnement tumoral , Vésicules extracellulaires/immunologie , Vésicules extracellulaires/physiologie , Humains , Monocytes/immunologie , Microenvironnement tumoral/immunologie , Tumeurs/immunologie , Tumeurs/anatomopathologie , Macrophages/immunologie , Cytokines , Différenciation cellulaire
2.
J Dent ; 146: 105073, 2024 07.
Article de Anglais | MEDLINE | ID: mdl-38782176

RÉSUMÉ

OBJECTIVES: Evaluate, in vitro, the effect of incorporating nano-sized sodium trimetaphosphate (TMPnano) and phosphorylated chitosan (Chi-Ph) into resin-modified glass ionomer cement (RMGIC) used for orthodontic bracket cementation, on mechanical, fluoride release, antimicrobial and cytotoxic properties. METHODS: RMGIC was combined with Chi-Ph (0.25%/0.5%) and/or TMPnano (14%). The diametral compressive/tensile strength (DCS/TS), surface hardness (SH) and degree of conversion (%DC) were determined. For fluoride (F) release, samples were immersed in des/remineralizing solutions. Antimicrobial/antibiofilm activity was evaluated by the agar diffusion test and biofilm metabolism (XTT). Cytotoxicity in fibroblasts was assessed with the resazurin method. RESULTS: After 24 h, the RMGIC-14%TMPnano group showed a lower TS value (p < 0.001); after 7 days the RMGIC-14%TMPnano-0.25%Chi-Ph group showed the highest value (p < 0.001). For DCS, the RMGIC group (24 h) showed the highest value (p < 0.001); after 7 days, the highest value was observed for the RMGIC-14%TMPnano-0.25%Chi-Ph (p < 0.001). RMGIC-14%TMPnano, RMGIC-14%TMPnano-0.25%Chi-Ph, RMGIC-14%TMPnano-0.5%Chi-Ph showed higher and similar release of F (p > 0.001). In the SH, the RMGIC-0.25%Chi-Ph; RMGIC-0.5%Chi-Ph; RMGIC-14%TMPnano-0.5%Chi-Ph groups showed similar results after 7 days (p > 0.001). The RMGIC-14%TMPnano-0.25%Chi-Ph group showed a better effect on microbial/antibiofilm growth, and the highest efficacy on cell viability (p < 0.001). After 72 h, only the RMGIC-14%TMPnano-0.25%Chi-Ph group showed cell viability (p < 0.001). CONCLUSION: The RMGIC-14%TMPnano-0.25%Chi-Ph did not alter the physical-mechanical properties, was not toxic to fibroblasts and reduced the viability and metabolism of S. mutans. CLINICAL RELEVANCE: The addition of phosphorylated chitosan and organic phosphate to RMGIC could provide an antibiofilm and remineralizing effect on the tooth enamel of orthodontic patients, who are prone to a high cariogenic challenge due to fluctuations in oral pH and progression of carious lesions.


Sujet(s)
Antibactériens , Biofilms , Chitosane , Fibroblastes , Fluorures , Ciment ionomère au verre , Test de matériaux , Chitosane/pharmacologie , Antibactériens/pharmacologie , Ciment ionomère au verre/pharmacologie , Ciment ionomère au verre/composition chimique , Biofilms/effets des médicaments et des substances chimiques , Fibroblastes/effets des médicaments et des substances chimiques , Phosphorylation , Fluorures/pharmacologie , Dureté , Résistance à la traction , Propriétés de surface , Résistance à la compression , Nanoparticules , Céments résine/composition chimique , Polyphosphates/pharmacologie , Ciments dentaires/pharmacologie , Ciments dentaires/composition chimique , Survie cellulaire/effets des médicaments et des substances chimiques , Streptococcus mutans/effets des médicaments et des substances chimiques , Animaux , Phosphates/pharmacologie , Humains , Brackets orthodontiques
3.
Anim Reprod Sci ; 265: 107475, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38663149

RÉSUMÉ

A greater understanding of factors influencing fertility is essential to improve pregnancy rates and reduce the occurrence of embryonic mortality in beef herds. The objective of the current study was to evaluate retrospective data of pregnancy per artificial insemination (P/AI) and pregnancy loss in Nelore females subjected to timed-AI (TAI) in Brazil. Data from 40,104 TAI collected from six breeding seasons (2016-2022) were analyzed, and the effects of animal category (e.g., classification based on age and parity), farm, month of parturition, sire, sire breed (Nelore vs Angus), estrus expression at TAI, animal temperament, and body condition scores (BCS) were evaluated. P/AI and pregnancy loss were affected (P < 0.001) by animal category. There was also an effect of farm (P = 0.0013) on P/AI and pregnancy loss (P = 0.001), as P/AI ranged from 49.28% and 55.58% and pregnancy loss from 3.37% to 6.89% across the herds evaluated. Month of parturition also affected (P < 0.001) P/AI and was higher for cows that became pregnant at the beginning of the previous breeding season. Calmer animals, presenting lower velocity scores while exiting the chute following TAI, achieved higher P/AI (P < 0.001). Lower BCS at TAI was associated (P < 0.001) with increased pregnancy loss, and BCS gain following AI was associated (P < 0.001) with reduced rates of embryonic mortality. There was a major effect (P < 0.001) of sire on P/AI and pregnancy loss, as P/AI ranged from 11% to 79%, and embryonic mortality from 0% to 40% for the bulls used in the study, highlighting the importance of the sire fertility on overall pregnancy success. Results from the current study reinforce the idea that animal age and parity at the beginning of the breeding season, BCS at the onset of estrous synchronization, BCS gain following AI, estrus expression at TAI, sire, and month of parturition are important factors influencing P/AI and rates of embryonic mortality in beef herds.


Sujet(s)
Insémination artificielle , Animaux , Femelle , Grossesse , Bovins/physiologie , Insémination artificielle/médecine vétérinaire , Brésil , Études rétrospectives , Taux de grossesse , Synchronisation de l'oestrus , Avortement chez les animaux
4.
Rev. bras. oftalmol ; 83: e0033, 2024. graf
Article de Anglais | LILACS | ID: biblio-1565362

RÉSUMÉ

ABSTRACT This case series describes four patients who presented with retinal and optic nerve vascular occlusions after administration of different COVID-19 vaccines. The first patient received the ChAdOx1 nCoV-19 vaccine (AZD1222; Oxford/AstraZeneca) and 42 days later developed central retinal artery occlusion. The second patient developed a painless visual impairment in the left eye and was diagnosed with anterior ischemic optic neuropathy 6 days after receiving the Sinovac-CoronaVac vaccine. The third patient presented with the same condition 22 days after receiving the third dose of the COVID-19 Pfizer (Comirnaty®) vaccine. The fourth patient developed bilateral retrobulbar optic neuritis after receiving the Oxford/AstraZeneca vaccine. The purpose of this case series is to discuss the possibility of a causal association between ischemic eye alterations and COVID-19 virus vaccination. Long-term follow-up and evaluation of similar cases will help elucidate the degree of the association between the vaccine and ischemic ocular events.


RESUMO Esta série de casos descreve quatro casos de pacientes que apresentaram oclusões vasculares de retina e nervo óptico após a administração de tipos diferentes de vacinas contra COVID-19. O primeiro paciente tomou a vacina ChAdOx1 nCoV-19 (AZD1222; Oxford/AstraZeneca) e 42 dias depois desenvolveu oclusão da artéria central da retina. O segundo paciente teve défice visual indolor no olho esquerdo após 6 dias da vacina Sinovac (CoronaVac) e foi diagnosticado com neuropatia óptica isquêmica anterior. O terceiro paciente apresentou o mesmo quadro após 22 dias da terceira dose da vacina COVID-19 Pfizer (Comirnaty®). O quarto paciente desenvolveu neurite óptica retrobulbar bilateral após vacina Oxford/AstraZeneca. O objetivo da nossa série de casos é discutir a possibilidade de correlação entre os quadros oculares isquêmicos e a vacinação contra a COVID-19. Nossos pacientes receberam vacinas contra COVID-19 com tecnologias diferentes e apresentaram quadros isquêmicos oculares relacionados temporalmente à vacinação. O acompanhamento e a avaliação a longo prazo de novos estudos semelhantes elucidarão o grau de associação entre a vacina e esse possível evento adverso.


Sujet(s)
Humains , Mâle , Femelle , Adulte d'âge moyen , Sujet âgé , Occlusion artérielle rétinienne/étiologie , Névrite optique/étiologie , Neuropathie optique ischémique/étiologie , Vaccins contre la COVID-19/effets indésirables , Occlusion artérielle rétinienne/diagnostic , Névrite optique/diagnostic , Vaccination/effets indésirables , Neuropathie optique ischémique/diagnostic , Effets secondaires indésirables des médicaments
5.
Purinergic Signal ; 2023 Nov 17.
Article de Anglais | MEDLINE | ID: mdl-37975950

RÉSUMÉ

Trypanosoma cruzi is the pathogen of Chagas disease, a neglected tropical disease that affects more than 6 million people worldwide. There are no vaccines to prevent infection, and the therapeutic arsenal is very minimal and toxic. The unique E-NTPDase of T. cruzi (TcNTPDase1) plays essential roles in adhesion and infection and is a virulence factor. Quercetin is a flavonoid with antimicrobial, antiviral, and antitumor activities. Its potential as a partial inhibitor of NTPDases has also been demonstrated. In this work, we synthesized the non-natural L-glycoside derivatives of quercetin and evaluated them as inhibitors of recombinant TcNTPDase1 (rTcNTPDase1). These compounds, and quercetin and miquelianin, a natural quercetin derivative, were also tested. Compound 16 showed the most significant inhibitory effect (94%). Quercetin, miquelianin, and compound 14 showed inhibition close to 50%. We thoroughly investigated the inhibitory effect of 16. Our data suggested a competitive inhibition with a Ki of 8.39 µM (± 0.90). To better understand the interaction of compound 16 and rTcNTPDase1, we performed molecular dynamics simulations of the enzyme and docking analyses with the compounds. Our predictions show that compound 16 binds to the enzyme's catalytic site and interacts with important residues for NTPDase activity. As an inhibitor of a critical T. cruzi enzyme, (16) could be helpful as a starting point in the developing of a future treatment for Chagas disease. Furthermore, the discovery of (16) as an inhibitor of TcNTPDase1 may open new avenues in the study and development of new inhibitors of E-NTPDases.

6.
Purinergic Signal ; 2023 Nov 24.
Article de Anglais | MEDLINE | ID: mdl-37999896

RÉSUMÉ

Leishmania braziliensis is a pathogenic protozoan parasite that causes American Tegumentary Leishmaniasis (ATL), an important tropical neglected disease. ENTPDases are nucleotidases that hydrolyze intracellular and/or extracellular nucleotides. ENTPDases are known as regulators of purinergic signalling induced by extracellular nucleotides. Leishmania species have two isoforms of ENTPDase, and, particularly, ENTPDase2 seems to be involved in infectivity and virulence. In this study, we conducted the heterologous expression and biochemical characterization of the recombinant ENTPDase2 of L. braziliensis (rLbNTPDase2). Our results show that this enzyme is a canonical ENTPDase with apyrase activity, capable of hydrolysing triphosphate and diphosphate nucleotides, and it is dependent on divalent cations (calcium or magnesium). Substrate specificity was characterized as UDP>GDP>ADP>GTP>ATP=UTP. The enzyme showed optimal activity at a neutral to basic pH and was partially inhibited by suramin and DIDS. Furthermore, the low apparent Km for ADP suggests that the enzyme may play a role in adenosine-mediated signalling. The biochemical characterization of this enzyme can open new avenues for using LbNTPDase2 as a drug target.

7.
Sensors (Basel) ; 23(13)2023 Jun 26.
Article de Anglais | MEDLINE | ID: mdl-37447772

RÉSUMÉ

Traffic Sign Recognition (TSR) is one of the many utilities made possible by embedded systems with internet connections. Through the usage of vehicular cameras, it's possible to capture and classify traffic signs in real time with Artificial Intelligence (AI), more specifically, Convolutional Neural Networks (CNNs) based techniques. This article discusses the implementation of such TSR systems, and the building process of datasets for AI training. Such datasets include a brand new class to be used in TSR, vegetation occlusion. The results show that this approach is useful in making traffic sign maintenance faster since this application turns vehicles into moving sensors in that context. Leaning on the proposed technique, identified irregularities in traffic signs can be reported to a responsible body so they will eventually be fixed, contributing to a safer traffic environment. This paper also discusses the usage and performance of different YOLO models according to our case studies.


Sujet(s)
Intelligence artificielle , Apprentissage profond , Brésil , Internet , 29935
8.
Pharmaceuticals (Basel) ; 16(2)2023 Jan 30.
Article de Anglais | MEDLINE | ID: mdl-37259357

RÉSUMÉ

Targeted antitumour therapy has revolutionized the treatment of several types of tumours. Among the validated targets, phosphatidylinositol-3 kinase (PI3K) deserves to be highlighted. Several PI3K inhibitors have been developed for the treatment of cancer, including gedatolisib (4). This inhibitor was elected as a prototype and molecular modifications were planned to design a new series of simplified gedatolisib analogues (5a-f). The analogues were synthesised, and the comparative cytotoxic activity profile was studied in phenotypic models employing solid and nonadherent tumour cell lines. Compound 5f (LASSBio-2252) stood out as the most promising of the series, showing good aqueous solubility (42.38 µM (pH = 7.4); 39.33 µM (pH = 5.8)), good partition coefficient (cLogP = 2.96), cytotoxic activity on human leukemia cell lines (CCRF-CEM, K562 and MOLT-4) and an excellent metabolic stability profile in rat liver microsomes (t1/2 = 462 min; Clapp = 0.058 mL/min/g). The ability of 5f to exert its cytotoxic effect through modulation of the PI3K pathway was demonstrated by flow cytometry analysis in a comparative manner to gedatolisib.

9.
Saúde Redes ; 9(2): 21, jun. 2023.
Article de Portugais | LILACS-Express | LILACS | ID: biblio-1444171

RÉSUMÉ

No Brasil, as medidas de isolamento social para o enfrentamento à propagação do COVID-19 demandaram a paralisação das atividades presenciais das escolas médicas. Com a pequena quantidade de estudos que tratam das práticas pedagógicas utilizadas nesse período, este artigo busca analisar por meio de uma revisão da literatura as experiências de Instituições de Ensino Superior brasileiras durante a pandemia de COVID-19, entendendo seu impacto na formação de novos médicos. Os dados foram coletados nos bancos de dados PUBMED e Biblioteca Virtual em Saúde, com a inclusão de 20 trabalhos publicados de abril de 2020 a dezembro de 2022. A partir do conteúdo dos textos selecionados, criouse quatro categorias a serem consideradas. Após análise, conclui-se que o ensino remoto trouxe diversas consequências negativas para o processo de ensino-aprendizagem na formação médica. Foram evidenciados aspectos como a ampliação das dificuldades de acesso à educação encontrada por estudantes de baixa renda, além do deterioramento da saúde mental de docentes e discentes. Quanto às novas estratégias pedagógicas, percebeu-se uso de ferramentas digitais e metodologias ativas com caráter emergencial e temporário, consideradas satisfatórias, em sua maioria, mas repletas de insuficiências quanto à qualidade de ensino.

10.
Front Immunol ; 14: 886601, 2023.
Article de Anglais | MEDLINE | ID: mdl-36960058

RÉSUMÉ

Introduction: Pulmonary fibrosis is a destructive, progressive disease that dramatically reduces life quality of patients, ultimately leading to death. Therapeutic regimens for pulmonary fibrosis have shown limited benefits, hence justifying the efforts to evaluate the outcome of alternative treatments. Methods: Using a mouse model of bleomycin (BLM)-induced lung fibrosis, in the current work we asked whether treatment with pro-resolution molecules, such as pro-resolving lipid mediators (SPMs) could ameliorate pulmonary fibrosis. To this end, we injected aspirin-triggered resolvin D1 (7S,8R,17R-trihydroxy-4Z,9E,11E,13Z,15E19Z-docosahexaenoic acid; ATRvD1; i.v.) 7 and 10 days after BLM (intratracheal) challenge and samples were two weeks later. Results and discussion: Assessment of outcome in the lung tissues revealed that ATRvD1 partially restored lung architecture, reduced leukocyte infiltration, and inhibited formation of interstitial edema. In addition, lung tissues from BLM-induced mice treated with ATRvD1 displayed reduced levels of TNF-α, MCP-1, IL-1-ß, and TGF-ß. Of further interest, ATRvD1 decreased lung tissue expression of MMP-9, without affecting TIMP-1. Highlighting the beneficial effects of ATRvD1, we found reduced deposition of collagen and fibronectin in the lung tissues. Congruent with the anti-fibrotic effects that ATRvD1 exerted in lung tissues, α-SMA expression was decreased, suggesting that myofibroblast differentiation was inhibited by ATRvD1. Turning to culture systems, we next showed that ATRvD1 impaired TGF-ß-induced fibroblast differentiation into myofibroblast. After showing that ATRvD1 hampered extracellular vesicles (EVs) release in the supernatants from TGF-ß-stimulated cultures of mouse macrophages, we verified that ATRvD1 also inhibited the release of EVs in the bronco-alveolar lavage (BAL) fluid of BLM-induced mice. Motivated by studies showing that BLM-induced lung fibrosis is linked to angiogenesis, we asked whether ATRvD1 could blunt BLM-induced angiogenesis in the hamster cheek pouch model (HCP). Indeed, our intravital microscopy studies confirmed that ATRvD1 abrogates BLM-induced angiogenesis. Collectively, our findings suggest that treatment of pulmonary fibrosis patients with ATRvD1 deserves to be explored as a therapeutic option in the clinical setting.


Sujet(s)
Fibrose pulmonaire , Humains , Fibrose pulmonaire/induit chimiquement , Fibrose pulmonaire/traitement médicamenteux , Fibrose pulmonaire/métabolisme , Acide acétylsalicylique/pharmacologie , Acide docosahexaénoïque/pharmacologie , Acide docosahexaénoïque/usage thérapeutique , Poumon/anatomopathologie , Bléomycine/pharmacologie , Facteur de croissance transformant bêta/métabolisme
11.
Polymers (Basel) ; 15(1)2023 Jan 03.
Article de Anglais | MEDLINE | ID: mdl-36616585

RÉSUMÉ

Recent formulations of resin-based composites have incorporated different combinations of materials. However, the mechanical and bonding behavior of these materials with intraradicular posts are unclear. This study aimed to evaluate the effect of light-cure and dual-cure resin composite posts on the fracture resistance of endodontically-treated teeth. Materials and Methods: Ninety extracted human upper canines were selected and randomly divided into nine groups (n=10): (G1) endodontically treated teeth without endodontic posts; (G2) glass-fiber post cemented with glass-ionomer cement; (G3) endodontic post by dual-cure composite resin (Rebilda DC); (G4) endodontic post by dual-cure composite resin (Cosmecore); (G5) endodontic post by dual-cure composite resin (Bis-Core); (G6) endodontic post by light-cure composite resin; (G7) glass-fiber post customized with flowable composite resin; (G8) glass-fiber post cemented with light-cure composite resin; (G9) glass-fiber post cemented with self-adhesive resin cement. After the post insertion, all specimens were subjected to mechanical (250,000 cycles) and thermocycling (6000 cycles, 5 °C/55 °C) and immediate loading at 45 degrees in a universal testing machine until fracture. The data were analyzed by one-way ANOVA and multiple comparisons using the Fisher LSD Method (p < 0 05). Results: The mean failure loads (±SD) for the groups ranged from 100.7 ± 22.6 N to 221.9 ± 48.9 N. The G1 group (without endodontic posts) had a higher fracture strength than all experimental groups (p < 0.001). Conclusions: Within the limitations, the light- and dual-cure post technique did not present lower fracture resistance values as compared to the conventional glass-fiber post.

12.
Toxicon ; 223: 107011, 2023 Feb.
Article de Anglais | MEDLINE | ID: mdl-36584790

RÉSUMÉ

Envenomation by Bothrops snakes and Apis mellifera bee may imply systemic disorders which affect well-perfused organs such as kidneys, a process that can lead to acute renal failure. Nevertheless, there is scarce information regarding a direct renal cell effect and the putative antagonism by antivenoms. Here the cytotoxic effect of B. jararacussu and A. mellifera venoms was evaluated in the renal proximal tubule cell line LLC-PK1, as well as the antagonism of this effect by heparin. B. jararacussu venom showed significant cytotoxicity as assessed by LDH release and MTT reduction, with a sharp decline of the cell number after 180 min (>90% at 50 µg/mL). A. mellifera venom produced a much faster and potent cytotoxic activity, conferring almost no viable cells after 15 min at 25 µg/mL. Phase contrast microscopy revealed that while B. jararacussu venom induced a progressive loss of cell adhesion and detachment, A. mellifera venom promoted a rapid plasma membrane disruption and nuclear condensation suggestive of necrotic cell death. Pre-incubation of both venoms with heparin for 30 min significantly reduced cytotoxicity. Our results demonstrate direct toxicity of B. jararacussu and A. mellifera venoms toward renal cells but with distinct kinetics and cell pattern, suggesting different mechanisms of action. In addition, the antagonistic, cytoprotective effect of heparin ascribes such compound as a promising drug for preventing renal failure from envenomation.


Sujet(s)
Antinéoplasiques , Bothrops , Venins de crotalidé , Abeilles , Animaux , Héparine/pharmacologie , Sérums antivenimeux/pharmacologie , Venins de crotalidé/toxicité , Rein
13.
J Prosthet Dent ; 2022 Nov 10.
Article de Anglais | MEDLINE | ID: mdl-36372587

RÉSUMÉ

STATEMENT OF PROBLEM: Computer-guided implant surgery facilitated by intraoral scanning may enhance the efficiency of the digital workflow. However, it is necessary to assess technique accuracy to evaluate the accuracy of implant placement. PURPOSE: The purpose of this clinical study was to evaluate the accuracy of a virtual computer-aided design and computer-aided manufacturing (CAD-CAM) static guided surgery technique associated with intraoral scanning in partially edentulous participants by analyzing the overlap among preoperative and postoperative cone beam computed tomography (CBCT) scans, virtual planning, and the guided surgery performed. MATERIAL AND METHODS: Eleven partially edentulous participants underwent CBCT and intraoral scanning (TRIOS3). Data were integrated into a software program (ImplantViewer 3.5) for the virtual planning of implants and 3-dimensional (3D) printing of the prototype CAD-CAM surgical guide. A total of 18 implants were placed using the CAD-CAM static computer-aided implant surgery technique (Strong SW). After 15 days, postoperative CBCT scans were made and 4 variables (angular, coronal, apical, and vertical deviation) were measured to compare the virtually planned implants and the implants placed by analyzing the overlap between preoperative and postoperative of the virtual planning and guided surgery performed using the ImplantViewer 3.5 and Rhino 6 software programs. RESULTS: Deviations were found in all parameters analyzed. The mean angular deviation was 2.68 ±1.62 degrees; mean coronal deviation, 0.82 ±0.44 mm; mean apical deviation, 1.14 ±0.44 mm; and mean vertical deviation, 0.62 ±0.44 mm. CONCLUSIONS: The implants placed using the CAD-CAM static guided surgery technique associated with intraoral scanning in partially edentulous participants exhibited angular and linear deviations when compared with virtual planning implants. However, these deviations were not clinically significant.

14.
Polymers (Basel) ; 14(19)2022 Sep 26.
Article de Anglais | MEDLINE | ID: mdl-36235967

RÉSUMÉ

Resin-based composites (RBCs) have transformed restorative dentistry and its procedures. However, the characteristics of RBCs have been modified over the years to enhance the physical and chemical properties of the materials. This context raises the need for studies that evaluate whether the properties of the RBCs that are commercially available are clinically adequate with different curing modes. This study aimed to evaluate the mechanical behavior of commercial RBCs after undergoing different curing modes. Twenty-three RBCs of different classes were evaluated. For curing the specimens, a microwave (BMS45, Brastemp) (for 3 min at 450 W) and three LED units were used: an Emitter A Fit (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1250 mW/cm2), VALO (Ultradent (third generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2), and Emitter Now Duo (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2). A total of 670 RBC specimens of 8 mm in diameter and 1 mm in depth were obtained. Afterward, a biaxial flexure strength test was performed until the failure of the specimens, using a universal testing machine set at a speed of 0.5 mm/min. The same specimens were subjected to infrared spectroscopy for evaluating the degree of conversion. Tukey's test was used for multiple comparisons at a significance level of 5%. The light-curing mode did not affect the flexure strength of the RBCs (p > 0.05), but the type and shade of RBCs did so (p < 0.05). In conclusion, the type of RBC directly interferes with the mechanical behavior of the material. However, the curing modes within the same RBC did not change the mechanical properties.

16.
Cells ; 11(12)2022 06 09.
Article de Anglais | MEDLINE | ID: mdl-35741003

RÉSUMÉ

Immune system cells, including neutrophils, are recruited by the tumor microenvironment as a site of chronic inflammation and begin to favor tumor growth. Neutrophils present in the tumor site are called tumor-associated neutrophils (TAN) and can present two phenotypes: N1 (antitumor) or N2 (pro-tumor). Evidence shows the high capacity of immune system cells to interact with extracellular vesicles (Evs) released by tumor cells. Evs can modulate the phenotype of cells within the immune system, contributing to tumor development. Here, we investigated the role of MDA-MB-231-derived Evs upon the polarization of neutrophils towards an N2 phenotype and the underlying mechanisms. We observed that neutrophils treated with Evs released by MDA cells (MDA-Evs) had their half-life increased, increased their chemotactic capacity, and released higher levels of NETs and ROS than neutrophils treated with non-tumoral Evs. We also observed that neutrophils treated with MDA-Evs released increased IL-8, VEGF, MMP9, and increased expression of CD184, an N2-neutrophil marker. Finally, neutrophils treated with MDA-Evs increased tumor cell viability. Our results show that MDA-Evs induce an N2-like phenotype, and the blockage of phosphatidylserine by annexin-V may be an essential agent counter-regulating this effect.


Sujet(s)
Vésicules extracellulaires , Tumeurs , Survie cellulaire , Vésicules extracellulaires/métabolisme , Humains , Tumeurs/métabolisme , Granulocytes neutrophiles/métabolisme , Microenvironnement tumoral
17.
Anal Biochem ; 646: 114648, 2022 06 01.
Article de Anglais | MEDLINE | ID: mdl-35276071

RÉSUMÉ

Lateral flow immunochromatography is a widely used technique for immunological assays. Construction of test and control lines is mostly done by antigen adsorption to nitrocellulose membranes, a process not fully understood. This study aimed to evaluate the influence of urea, salts, and Tween 20, on adsorption. The performance of canine IgG in water and in buffer containing urea and salts (pH 8.3) were compared to observe if the interferents would lead to protein stripping when challenged with increasing concentrations of Tween 20 in the lateral flow buffer. Immobilization of the rLiNTPDase2, an antigen for Canine Leishmaniasis diagnosis, was evaluated and compared to the rLbNTPDase2 by the same method. There were no differences between adsorption coefficients of IgG in water and in buffer, but high salt and urea concentrations seems to stabilize and enhance IgG immobilization. Adsorption performance between canine IgG and rNTPDases had different patterns, but was highly similar between rNTPDases, indicating that protein identity may have an important role. Also, low concentrations of Tween 20 in the flow solution may aid the maintenance of rNTPDase2 on the strips. Our results bring insights about protein adsorption and perspectives about the influence of urea, salts and Tween 20 on this process.


Sujet(s)
Leishmania , Polysorbates , Adsorption , Animaux , Collodion , Chiens , Immunoglobuline G , Polysorbates/composition chimique , Sels , Urée , Eau
18.
J Appl Oral Sci ; 30: e20210483, 2022.
Article de Anglais | MEDLINE | ID: mdl-35352770

RÉSUMÉ

OBJECTIVES: To evaluate the mechanical, physicochemical, and antimicrobial properties of four different formulations containing micro- or nanoparticles of sodium trimetaphosphate (mTMP and nTMP, respectively). METHODOLOGY: Four experimental groups were used in this investigation: two mTMP groups and two nTMP groups, each containing zirconium oxide (ZrO2), and solution containing either chitosan or titanium oxide (TiO2) nanoparticles (NPs). Setting time, compression resistance, and radiopacity were estimated. The agar diffusion test was used to assess the antimicrobial activity of the formulations against five different microbial strains: Streptococcus mutans, Lactobacillus casei, Actinomyces israelii, Candida albicans, and Enterococcus faecalis. Parametric and nonparametric tests were performed after evaluating homoscedasticity data (p<0.05). RESULTS: From the properties evaluated, nTMP cements required less setting time and showed greater resistance to compression. Cements containing TiO2 showed greater radiopacity for both nTMP and mTMP. All four cement formulations showed antimicrobial activity against S. mutans and L. casei. CONCLUSION: Formulations containing nTMP have shorter setting times and higher compressive strength, and those with TiO2 nanoparticles showed antimicrobial activities. Clinical relevance: The cement containing nTMP, ZrO2, and TiO2 could be an alternative material for protecting the pulp complex.


Sujet(s)
Anti-infectieux , Coiffage pulpaire , Antibactériens/composition chimique , Anti-infectieux/pharmacologie , Ciments dentaires/composition chimique , Polyphosphates
19.
Vet Parasitol ; 301: 109638, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-34920304

RÉSUMÉ

Canine visceral leishmaniasis (CVL) is the most aggressive and lethal form of leishmaniasis manifesting in dogs and represents a major public health concern. Although there are sufficiently sensitive molecular tools for CVL diagnosis, they are not accessible at the main points of disease dissemination, in which context serodiagnosis has been used as an alternative tool on the epidemiological control. As an attempt to develop more accurate immunodiagnostic assays, many antigens have been tested over the years, on different platforms. This review aimed to access studies reporting new antigens that can be applied for CVL serodiagnosis. Articles published from January of 2016 to March of 2021 were retrieved from Google Scholar, Science Direct, and PubMed, using "Canine Visceral Leishmaniasis" and "Serodiagnosis" as keywords. In total, 1527 articles were identified, of which 42 were selected based on exclusion factors. Sensitivity, specificity, sample size, and sample quality data were extracted by manual curation and analyzed. Of the selected articles, 26 contemplated ELISA, which enabled a more thorough comparison and a critical review of these studies. Soluble Leishmania Antigens (SLA) and the A2 protein were used as controls in 53.8 and 46.15 % of these articles, respectively, and were evaluated separately; their frequent use was questioned. Subsequently, articles that evaluated other assay platforms, such as immunochromatography, immunosensors, and others, were also reported and evaluated. Finally, data relative to validation studies of commercial kits were briefly discussed. Our results show that there are several antigens with great potential for the development of accurate diagnostic tools, but further testing is required. The critical analysis also brings insights that can be useful for more assertive diagnostic development of more robust tools for CVL serodiagnosis.


Sujet(s)
Techniques de biocapteur , Maladies des chiens , Leishmania infantum , Leishmaniose viscérale , Animaux , Antigènes de protozoaire , Techniques de biocapteur/médecine vétérinaire , Maladies des chiens/diagnostic , Chiens , Test ELISA/médecine vétérinaire , Dosage immunologique/médecine vétérinaire , Leishmaniose viscérale/diagnostic , Leishmaniose viscérale/médecine vétérinaire , Sensibilité et spécificité , Tests sérologiques/médecine vétérinaire
20.
Clin Oral Investig ; 26(2): 1561-1567, 2022 Feb.
Article de Anglais | MEDLINE | ID: mdl-34387730

RÉSUMÉ

OBJECTIVES: The presence of SARS-CoV-2 virus in the saliva of patients infected with COVID-19 has been confirmed by several studies. However, the use of saliva for the diagnosis of COVID-19 remains limited, because of the discrepancies in the results, which might be due to using different saliva sampling methods. The purpose of this study was to compare the consistency of SARS-CoV-2 detection using two different saliva sampling methods (oral swab and unstimulated saliva) to that of the standard nasopharyngeal swab. METHODS: Fifty-five subjects were recruited from a pool of COVID-19 inpatient at the Hospital Israelita Albert Einstein (HIAE), Brazil. Nasopharyngeal swab, oral swab, and self-collected unstimulated saliva samples were examined for SARS-CoV-2 using RT-PCR. RESULTS: Self-collected unstimulated saliva demonstrated 87.3% agreement in the detection of SARS-CoV-2 virus as compared with the nasopharyngeal swab, while oral swab displayed 65.9% agreement when compared to nasopharyngeal swab and 73% when compared to self-collected unstimulated saliva. CONCLUSION: Unstimulated self-collected saliva samples have shown a higher agreement with the nasopharyngeal swab samples for SARS-COV-2 detection than that obtained when using oral swab samples. CLINICAL RELEVANCE: This study compares the accuracy of COVID-19 test using different saliva sampling methods to that of nasopharyngeal swab. Given the need for a simple self-applied test that can be performed at home, our findings support the efficacy of self-collected unstimulated saliva samples in the diagnosis of SARS-CoV-2 infection, alleviating the demands for swab supplies, personal protective equipment, and healthcare personnel.


Sujet(s)
COVID-19 , SARS-CoV-2 , Humains , Partie nasale du pharynx , Salive , Manipulation d'échantillons
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