RESUMO
We investigated molecular evolution and spatiotemporal dynamics of atypical Legionella pneumophila serogroup 1 sequence type 1905 and determined its long-term persistence and linkage to human disease in dispersed locations, far beyond the large 2014 outbreak epicenter in Portugal. Our finding highlights the need for public health interventions to prevent further disease spread.
Assuntos
Surtos de Doenças , Evolução Molecular , Legionella pneumophila , Doença dos Legionários , Análise Espaço-Temporal , Legionella pneumophila/genética , Legionella pneumophila/classificação , Portugal/epidemiologia , Humanos , Doença dos Legionários/epidemiologia , Doença dos Legionários/microbiologia , História do Século XXI , Recidiva , Filogenia , SorogrupoRESUMO
Limited data are available on breakthrough COVID-19 in patients with hematologic malignancy (HM) after anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Adult patients with HM, ≥1 dose of anti-SARS-CoV-2 vaccine, and breakthrough COVID-19 between January 2021 and March 2022 were analyzed. A total of 1548 cases were included, mainly lymphoid malignancies (1181 cases, 76%). After viral sequencing in 753 cases (49%), the Omicron variant was prevalent (517, 68.7%). Most of the patients received ≤2 vaccine doses before COVID-19 (1419, 91%), mostly mRNA-based (1377, 89%). Overall, 906 patients (59%) received COVID-19-specific treatment. After 30-day follow-up from COVID-19 diagnosis, 143 patients (9%) died. The mortality rate in patients with the Omicron variant was 7.9%, comparable to other variants, with a significantly lower 30-day mortality rate than in the prevaccine era (31%). In the univariable analysis, older age (P < .001), active HM (P < .001), and severe and critical COVID-19 (P = .007 and P < .001, respectively) were associated with mortality. Conversely, patients receiving monoclonal antibodies, even for severe or critical COVID-19, had a lower mortality rate (P < .001). In the multivariable model, older age, active disease, critical COVID-19, and 2-3 comorbidities were correlated with a higher mortality, whereas monoclonal antibody administration, alone (P < .001) or combined with antivirals (P = .009), was protective. Although mortality is significantly lower than in the prevaccination era, breakthrough COVID-19 in HM is still associated with considerable mortality. Death rate was lower in patients who received monoclonal antibodies, alone or in combination with antivirals.
Assuntos
COVID-19 , Neoplasias Hematológicas , Adulto , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2 , Teste para COVID-19 , Neoplasias Hematológicas/complicações , Neoplasias Hematológicas/terapia , Anticorpos Monoclonais , Antivirais , Anticorpos AntiviraisRESUMO
BACKGROUD: Although not fully investigated, studies show that Legionella pneumophila can develop antibiotic resistance. As there is limited data available for Portugal, we determined the antibiotic susceptibility profile of Portuguese L. pneumophila serogroup 1 (LpnSg1) isolates against antibiotics used in the clinical practice in Portugal. METHODS: Minimum inhibitory concentrations (MICs) were determined for LpnSg1 clinical (n = 100) and related environmental (n = 7) isolates, collected between 2006-2022 in the context of the National Legionnaire´s Disease Surveillance Programme, against azithromycin, clarithromycin, erythromycin, levofloxacin, ciprofloxacin, moxifloxacin, rifampicin, doxycycline, tigecycline, and amoxicillin/clavulanic acid, using three different assays. Isolates were also PCR-screened for the presence of the lpeAB gene. RESULTS: Twelve isolates had azithromycin MICs above the EUCAST tentative highest WT MIC, 9 of which were lpeAB negative; for erythromycin and clarithromycin, all isolates tested within the susceptible range. The number of isolates with MICs above the tentative highest WT MIC for the remaining antibiotics was: ciprofloxacin: 7; levofloxacin: 17; moxifloxacin: 8; rifampicin: 11; doxycycline: 82; tigecycline: 4. EUCAST breakpoints are not available for amoxicillin/clavulanic acid. We estimated the ECOFFs and one isolate had a MIC eightfold higher than the E-test ECOFF. Additionally, a clinical isolate generated three colonies growing on the E-test inhibition zone that resulted in MICs fourfold higher than for the parental isolate. CONCLUSIONS: We report, for the first time, elevated MICs against first-line and other antibiotics (including azithromycin, fluoroquinolones and amoxicillin/clavulanic acid commonly used to treat pneumonia patients in Portugal) in Portuguese L. pneumophila strains. Results point towards decreased susceptibility in circulating strains, justifying further investigation.
Assuntos
Antibacterianos , Azitromicina , Legionella pneumophila , Doença dos Legionários , Testes de Sensibilidade Microbiana , Portugal , Antibacterianos/farmacologia , Legionella pneumophila/efeitos dos fármacos , Legionella pneumophila/genética , Legionella pneumophila/isolamento & purificação , Legionella pneumophila/classificação , Humanos , Azitromicina/farmacologia , Doença dos Legionários/microbiologia , Sorogrupo , Farmacorresistência BacterianaRESUMO
Parasites comprise a substantial portion of global biodiversity and play critical roles in shaping ecosystems by modulating trophic networks and affecting their hosts' abundance and distribution. The dynamics of host migration introduce new complexity to these relationships. From the host perspective, migratory behavior can either act as a defense mechanism or augment exposure to a broader spectrum of pathogens. Conversely, for parasites, host migration represents a mechanism for their dispersion and an opportunity to infect new host species. This study investigates the complex interplay between migration and parasite-host interactions, focusing on the interaction between hosts and avian malaria and malaria-like parasites in the Brazilian Atlantic Rain Forest. We captured 1466 birds representing 70 different species, uncovering 322 infections with Plasmodium/Haemoproteus parasites. We observed variations in migration timing and fluctuations in host abundance across months. By comparing the observed patterns of interaction of migratory and non-migratory birds to patterns of interaction expected at random, we show that migration affects the roles hosts take in the parasite-host network. Interestingly, despite the fact migratory species hosted more exclusive and distinct parasites, migrants did not occupy central network positions, which are mostly occupied by resident birds. Overall, we highlight the role of resident birds as a key species within parasite-host communities and the high specialization among avian haemosporidians and their hosts.
Assuntos
Migração Animal , Aves , Interações Hospedeiro-Parasita , Animais , Brasil , Ecossistema , Plasmodium/fisiologiaRESUMO
INTRODUCTION AND HYPOTHESIS: In women with predominant stress urinary incontinence (SUI), recent data are still controversial regarding the short-term outcomes of mini-slings and there is a lack of evidence about the outcomes in the long term. Our aim was to evaluate the long-term effectiveness and complication rates of Altis® (Coloplast). METHODS: A total of 145 women with clinical SUI were implanted with an Altis® sling between April 2012 and December 2015. Women completed the International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF) before the intervention and in the following consultations. A telephone interview was performed in January 2021 and 131 women (90%) were available for re-evaluation. The main outcome was treatment success, defined as no self-reported SUI symptoms and no reintervention. Secondary outcomes included response to ICIQ-SF (cure defined as ICIQ-SF = 0) and Patient Global Impression of Improvement (PGI-I) questionnaires, de novo overactive bladder (OAB) symptoms and adverse events. RESULTS: The overall treatment success was 73.3% at a median follow-up of 8 years. The ICIQ-SF cure rate was 66.1%. In the PGI-I, 70.4% answered that they were much better or very much better. Later postoperative complications included 2 cases (1.5%) of vaginal extrusion (requiring surgical removal of the eroded mesh segment), 3 (2.3%) cases of infravesical obstruction (which led to sling section), de novo urgency in 20 patients (15.3%), and mild dyspareunia in 2 (1.5%) patients. CONCLUSIONS: The Altis® sling was safe and effective in a long-term follow-up, improving the quality of life in patients with SUI.
Assuntos
Slings Suburetrais , Incontinência Urinária por Estresse , Feminino , Humanos , Qualidade de Vida , Slings Suburetrais/efeitos adversos , Inquéritos e Questionários , Resultado do Tratamento , Incontinência Urinária por Estresse/etiologia , Incontinência Urinária por Estresse/cirurgiaRESUMO
Cardiotoxicity is one of the most serious side effects of cancer chemotherapy. Current approaches to monitoring of chemotherapy-induced cardiotoxicity (CIC) as well as model systems that develop in vivo or in vitro CIC platforms fail to notice early signs of CIC. Moreover, breast cancer (BC) patients with preexisting cardiac dysfunctions may lead to different incident levels of CIC. Here, a model is presented for investigating CIC where not only induced pluripotent stem cell (iPSC)-derived cardiac tissues are interacted with BC tissues on a dual-organ platform, but electrochemical immuno-aptasensors can also monitor cell-secreted multiple biomarkers. Fibrotic stages of iPSC-derived cardiac tissues are promoted with a supplement of transforming growth factor-ß 1 to assess the differential functionality in healthy and fibrotic cardiac tissues after treatment with doxorubicin (DOX). The production trend of biomarkers evaluated by using the immuno-aptasensors well-matches the outcomes from conventional enzyme-linked immunosorbent assay, demonstrating the accuracy of the authors' sensing platform with much higher sensitivity and lower detection limits for early monitoring of CIC and BC progression. Furthermore, the versatility of this platform is demonstrated by applying a nanoparticle-based DOX-delivery system. The proposed platform would potentially help allow early detection and prediction of CIC in individual patients in the future.
Assuntos
Neoplasias da Mama , Cardiotoxicidade , Neoplasias da Mama/tratamento farmacológico , Cardiotoxicidade/diagnóstico , Cardiotoxicidade/etiologia , Doxorrubicina/efeitos adversos , Feminino , Coração , Humanos , Dispositivos Lab-On-A-Chip , Miócitos CardíacosRESUMO
BACKGROUND: The first report of children born very preterm (<32 weeks of gestation) having insulin resistance was made 16 years ago. However, neonatal care has improved since. Thus, we aimed to assess whether children born very preterm still have lower insulin sensitivity than term controls. METHODS: Participants were prepubertal children aged 5 to 11 years born very preterm (<32 weeks of gestation; n = 51; 61% boys) or at term (37-41 weeks; n = 50; 62% boys). Frequently sampled intravenous glucose tolerance tests were performed, and insulin sensitivity was calculated using Bergman's minimal model. Additional clinical assessments included anthropometry, body composition using whole-body dual-energy X-ray absorptiometry scans, clinic blood pressure, and 24-hour ambulatory blood pressure monitoring. RESULTS: Children born very preterm were 0.69 standard deviation score (SDS) lighter (P < .001), 0.53 SDS shorter (P = .003), and had body mass index 0.57 SDS lower (P = .003) than children born at term. Notably, children born very preterm had insulin sensitivity that was 25% lower than term controls (9.4 vs 12.6 × 10-4 minutes-1 ·[mU/L]; P = .001). Other parameters of glucose metabolism, including fasting insulin levels, were similar in the two groups. The awake systolic blood pressure (from 24-hour monitoring) tended to be 3.1 mm Hg higher on average in children born very preterm (P = .054), while the clinic systolic blood pressure was 5.4 mm Hg higher (P = .002). CONCLUSIONS: Lower insulin sensitivity remains a feature of children born very preterm, despite improvements in neonatal intensive care. As reported in our original study, our findings suggest the defect in insulin action in prepubertal children born very pretermis primarily peripheral and not hepatic.
Assuntos
Resistência à Insulina , Fatores Etários , Pressão Sanguínea , Índice de Massa Corporal , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Idade Gestacional , Teste de Tolerância a Glucose , Humanos , Lactente Extremamente Prematuro , Recém-Nascido , Masculino , Fatores de RiscoRESUMO
INTRODUCTION: The lateral lumbar interbody fusion (LLIF) is a safe and effective technique to treat a vast range of lumbar disorders. However, the technique is also burdened by some problems. A new approach to the lateral lumbar interbody fusion was devised to solve or reduce some of the problems regarding the lateral approach. Its principal difference from the standard LLIF relies on positioning the patient in a prone decubitus, which might lead to an increase in the intradiscal lordosis. METHODS: A retrospective, multicentric, non-randomized study to evaluate segmental and regional lordosis following prone transpsoas (PTP) approach to LLIF. All patients undergoing prone transpsoas surgery at the involved institutions were included. Patients with low-quality images not allowing the measurements of the required spinopelvic parameters were excluded. Measurements included pre- and postoperative index-level segmental lordosis, lumbar lordosis, pelvic incidence, and pelvic tilt. RESULTS: Thirty-two (32) patients were included in the study, in which 23 underwent single-level, six (6) underwent two-level, Two (2) underwent three-level, and one underwent four-level PTP. Mean index level segmental lordosis increased from 8.7° to 14.8°(p < 0.001); lumbar lordosis (L1-S1) increased from 42.1° to 45.8° (p = 0.11), although after excluding an outlier value L1-S1 lordosis results were 41.9° pre-op to 46.7° post-op (p = 0.003). Twenty-two (22) patients had a pre-op PI-LL mismatch of 10° or more, while at the postoperative visit, only 12 patients had a mismatch outside of 10° (p = 0.01). CONCLUSION: The prone transpsoas technique is feasible and is associated with a significant gain of segmental lordosis and correction of spinopelvic alignment parameters.
Assuntos
Lordose , Fusão Vertebral , Humanos , Lordose/diagnóstico por imagem , Lordose/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Região Lombossacral , Estudos RetrospectivosRESUMO
Three-dimensional (3D) in vitro models, such as organ-on-a-chip platforms, are an emerging and effective technology that allows the replication of the function of tissues and organs, bridging the gap amid the conventional models based on planar cell cultures or animals and the complex human system. Hence, they have been increasingly used for biomedical research, such as drug discovery and personalized healthcare. A promising strategy for their fabrication is 3D printing, a layer-by-layer fabrication process that allows the construction of complex 3D structures. In contrast, 3D bioprinting, an evolving biofabrication method, focuses on the accurate deposition of hydrogel bioinks loaded with cells to construct tissue-engineered structures. The purpose of the present work is to conduct a systematic review (SR) of the published literature, according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, providing a source of information on the evolution of organ-on-a-chip platforms obtained resorting to 3D printing and bioprinting techniques. In the literature search, PubMed, Scopus, and ScienceDirect databases were used, and two authors independently performed the search, study selection, and data extraction. The goal of this SR is to highlight the importance and advantages of using 3D printing techniques in obtaining organ-on-a-chip platforms, and also to identify potential gaps and future perspectives in this research field. Additionally, challenges in integrating sensors in organs-on-chip platforms are briefly investigated and discussed.
Assuntos
Bioimpressão , Dispositivos Lab-On-A-Chip , Animais , Humanos , Hidrogéis , Impressão Tridimensional , Engenharia TecidualRESUMO
Despite the progress achieved in nanomedicine during the last decade, the translation of new nanotechnology-based therapeutic systems into clinical applications has been slow, especially due to the lack of robust preclinical tissue culture platforms able to mimic the in vivo conditions found in the human body and to predict the performance and biotoxicity of the developed nanomaterials. Organ-on-a-chip (OoC) platforms are novel microfluidic tools that mimic complex human organ functions at the microscale level. These integrated microfluidic networks, with 3D tissue engineered models, have been shown high potential to reduce the discrepancies between the results derived from preclinical and clinical trials. However, there are many challenges that still need to be addressed, such as the integration of biosensor modules for long-time monitoring of different physicochemical and biochemical parameters. In this review, recent advances on OoC platforms, particularly on the preclinical validation of nanomaterials designed for cancer, as well as the current challenges and possible future directions for an end-use perspective are discussed.
Assuntos
Microfluídica , Nanomedicina , Humanos , Dispositivos Lab-On-A-Chip , Análise de Sequência com Séries de Oligonucleotídeos , Engenharia TecidualRESUMO
Unfortunately, the third and fourth author names have been incorrectly published in the original publication. The complete correct names are given below.
Assuntos
Vacina de mRNA-1273 contra 2019-nCoV/administração & dosagem , Vacina BNT162/administração & dosagem , COVID-19 , Neoplasias Hematológicas , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/imunologia , COVID-19/mortalidade , COVID-19/prevenção & controle , Feminino , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/mortalidade , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Clostridium encompasses species which are relevant to human and animal disease as well as species which have industrial potential, for instance, as producers of chemicals and fuels or as tumour delivery vehicles. Genetic manipulation of these target organisms is critical for advances in these fields. DNA transfer efficiencies, however, vary between species. Low efficiencies can impede the progress of research efforts. A novel conjugal donor strain of Escherichia coli has been created which exhibits a greater than 10-fold increases in conjugation efficiency compared to the traditionally used CA434 strain in the three species tested; C. autoethanogenum DSM 10061, C. sporogenes NCIMB 10696 and C. difficile R20291. The novel strain, designated 'sExpress', does not methylate DNA at Dcm sites (CCWGG) which allows circumvention of cytosine-specific Type IV restriction systems. A robust protocol for conjugation is presented which routinely produces in the order of 105 transconjugants per millilitre of donor cells for C. autoethanogenum, 106 for C. sporogenes and 102 for C. difficile R20291. The novel strain created is predicted to be a superior conjugal donor in a wide range of species which possess Type IV restriction systems.
Assuntos
Clostridium/genética , Conjugação Genética , Escherichia coli/genética , Técnicas de Transferência de Genes , Genética Microbiana/métodosRESUMO
INTRODUCTION: Sleep related breathing disorders (SRBD) cause sleep fragmentation, intermittent hypoxia or a combination of both leading to homeostasis perturbations, including in the immune system. We investigated whether SRBD patients with or without intermittent hypoxia show substantial differences in perforin and granzyme-B positive peripheral blood lymphocytes. METHODS: A total of 87 subjects were included and distributed as follows: 24 controls (C), 19 patients with respiratory effort related arousals due to increased upper airway resistance (UAR) without hypoxic events, 24 obese patients with obstructive sleep apnea (OSA) (oOSA), and 20 without obesity (noOSA). After polysomnographic recording, we analyzed in fasting blood samples routine hematologic and biochemical parameters and the percentage of lymphocytes containing the proteins perforin and granzyme-B (GrB). Kruskal-Wallis tests and a posteriori multiple comparisons were applied for statistical analysis of results. RESULTS: Perforin-positive γδ-cells revealed significant differences between groups (p = 0.017), especially between the Control group and the oOSA (p-value = 0.04); the remaining SRBD groups also showed differences from the control (C vs UAR: p = 0.08; C vs noOSA = 0.09), but they did not raise to statistical significance. There were no differences among the SRBD groups. Granzyme-B cells were decreased in SRBD patients, but the differences were not statistically significant. No additional statistical significant result was found in the other investigated lymphocyte subsets. CONCLUSIONS: Obstructive sleep-disordered breathing is associated with a decrease in perforin-positive CD3+γδ-T cells. Although this finding was detected in lean patients without intermittent hypoxia, the reduction was only statistically significant in obese patients with severe OSA. Because CD3+γδ-T cells play an important role in the control of tumor cells, our findings are directly relevant for the study of the association of OSA and cancer.
Assuntos
Complexo CD3/metabolismo , Perforina/análise , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/imunologia , Linfócitos T/citologia , Linfócitos T/metabolismo , Adulto , Granzimas/análise , Granzimas/metabolismo , Humanos , Contagem de Linfócitos , Pessoa de Meia-Idade , Perforina/metabolismo , Polissonografia , Adulto JovemRESUMO
INTRODUCTION: The development of new surgical techniques and medical devices, like therapeutical multimodal approaches has allowed for better outcomes on patients with rectal cancer (RCa). Owing to that, an increased awareness and investment towards better outcomes regarding patients' sexual and urinary function has been recently observed. AIM: Evaluate and characterize the sexual dysfunction of patients submitted to surgical treatment for RCa. MATERIALS AND METHODS: An observational retrospective study including all male patients who underwent a surgical treatment for RCa between January 2011 December 2014 (n=43) was performed, complemented with an inquiry questionnaire to every patient about its sexual habits and level of function before and after surgery. DISCUSSION: All patients were male, with an average of 64yo. (range 42-83yo.). The surgical procedure was a rectum anterior resection (RAR) in 22 patients (56%) and an abdominoperineal resection (APR) in 19(44%). Sixty three percent described their sexual life as important/very important. Sexual function worsening was observed in 76% (65% with complains on erectile function, and 27% on ejaculation). Fourteen patients (38%) didn't resume sexual activity after surgery. Increased age (p=0.007), surgery performed (APR) (p=0.03) and the presence of a stoma (p=0.03) were predictors of ED after surgery. A secondary analysis found that the type of surgery (APR) (p=0.04), lower third tumor's location (p=0.03) and presence of comorbidities (p=0.013) (namely, smokers and diabetic patients) were predictors of de novo ED after surgery. CONCLUSIONS: This study demonstrated the clear negative impact in sexual function of patients submitted to a surgical treatment for RCa. Since it is a valued feature for patients, it becomes essential to correctly evaluate/identify these cases in order to offer an adequate therapeutical option.
Assuntos
Disfunção Erétil/etiologia , Complicações Pós-Operatórias , Neoplasias Retais/cirurgia , Reto/cirurgia , Disfunções Sexuais Fisiológicas/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Disfunção Erétil/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Autoavaliação (Psicologia) , Índice de Gravidade de Doença , Inquéritos e QuestionáriosRESUMO
A collaborative study was performed for the establishment of the 5th lot of Brazilian Bothrops Reference Venom and the 1st lot of Brazilian Bothrops Reference Antivenom. All Brazilian manufacturers of Antibothrops Immunoglobulins and the National Control Laboratory participated of the study. The declared potency of the 5th lot of the Bothrops Reference Venom is 40.29 µg/0.5 ml, and the potency of the 1st lot of Bothrops Reference Antivenom is 6.51 mg/ml. For the potency evaluation of Bothrops Reference Venom the inter assay precision (gCV) was 3.25% in lab 01; 3.51% in INCQS; 4.71% in lab 03 and 25.11% in lab 02, and the inter laboratory precision was 13.76%. The intra assay precision of Bothrops Reference Antivenom determinations was 4.38% in INCQS; 8.47% in lab 02; 10.51% in lab 03 and 20.05% in lab 01. The inter assay precision was 3.51% in INCQS; 9.65% in lab 02; 18.03% in lab 01 and 20.23% in lab 03. The inter laboratory precision was 15.85%. Despite the high number of invalid results (55.6% for the pharmacopoeial method and 69.4% for the proposed method) the parallel line assay, have better inter laboratorial precision (gCV = 16.62%) than the pharmacopoeial potency assay (gCV = 38.28%).
Assuntos
Antivenenos/análise , Bothrops , Venenos de Crotalídeos/análise , Animais , Brasil , Padrões de ReferênciaRESUMO
STATEMENT OF PROBLEM: Glass fiber post cementation procedures have undergone significant development. Relining the post with composite resin is a technique that aims to reduce resin cement thickness and consequently problems inherent to polymerization. Evidence is sparse regarding the efficacy of bonding procedures at increasing depths (from cervical to apical) using different adhesive cementation techniques. PURPOSE: The purpose of this in vitro study was to evaluate the push-out bond strength (PBS) of composite resin relined glass fiber posts cemented to bovine root dentin using different adhesive cementation protocols. MATERIAL AND METHODS: Eighteen bovine teeth (n=6) were embedded in polystyrene resin blocks, and the crowns were sectioned leaving a root portion of 20 mm in length. Root canals were prepared using rotary instruments provided by the post manufacturer (Whitepost DC #1), resulting in a uniform root canal preparation. The root canals were lubricated with a water-soluble glycerin gel. Silane (Prosil) was applied and the posts relined with a microhybrid composite resin (Filtek Z100) to conform to the root canal anatomy. Three adhesive cementation protocols were evaluated: a 3-step etch-and-rinse adhesive system (Adper Scotchbond Multi Purpose) in combination with a dual polymerizing resin cement (RelyX ARC); a universal adhesive system (Scotchbond Universal) associated with a dual polymerizing resin cement (RelyX Ultimate); and a self-adhesive dual polymerizing resin cement (RelyX Unicem 2). The roots were sectioned, resulting in four 2-mm segments at 4 different depths (cervical to apical) and evaluated by the PBS test, using a universal testing machine (Instron 4411) at 0.5 mm/min, until failure. Interfaces were evaluated by scanning electron microscopy, and failures were classified as cohesive failure in composite resin, cohesive failure in cement, cohesive failure in root dentin, adhesive failure, or mixed. Data were analyzed by 2-way split-plot ANOVA and the Tukey post hoc test (α=.05). RESULTS: No statistical differences were found for PBS when different cementation systems were compared (P=.253). Increased depths resulted in reduced PBS values for all cementation protocols evaluated (P<.001). CONCLUSIONS: Regardless the cementation system used, the lowest PBS values were at the apical region of resin relined glass fiber posts bonded to root dentin. Furthermore, the highest PBS is observed at the cervical portion of root dentin.
Assuntos
Descolagem Dentária , Adesivos Dentinários , Dentina , Vidro , Cimentos de Resina , Raiz Dentária , Animais , Bovinos , Técnicas In Vitro , Teste de MateriaisRESUMO
Blood flow presents several interesting phenomena in microcirculation that can be used to develop microfluidic devices capable to promote blood cells separation and analysis in continuous flow. In the last decade there have been numerous microfluidic studies focused on the deformation of red blood cells (RBCs) flowing through geometries mimicking microvessels. In contrast, studies focusing on the deformation of white blood cells (WBCs) are scarce despite this phenomenon often happens in the microcirculation. In this work, we present a novel integrative microfluidic device able to perform continuous separation of a desired amount of blood cells, without clogging or jamming, and at the same time, capable to assess the deformation index (DI) of both WBCs and RBCs. To determine the DI of both WBCs and RBCs, a hyperbolic converging microchannel was used, as well as a suitable image analysis technique to measure the DIs of these blood cells along the regions of interest. The results show that the WBCs have a much lower deformability than RBCs when subjected to the same in vitro flow conditions, which is directly related to their cytoskeleton and nucleus contents. The proposed strategy can be easily transformed into a simple and inexpensive diagnostic microfluidic system to simultaneously separate and assess blood cells deformability.