Hydroxyapatite crystallinity does not affect the repair of critical size bone defects

OBJECTIVE: The physicochemical properties of hydroxyapatite (HA) granules were observed to affect the biological behavior of graft materials. The aim of this work was to analyze the tissue response of two HA granules with different crystallinity and Ca/P ratio in vivo. MATERIAL AND METHODS: The HA granules were produced in the Biomaterials Laboratory (COPPE/UFRJ). The testing materials were HA granules presenting a Ca/P molar ratio of 1.60 and 28% crystallinity (HA-1), and a Ca/P molar ratio of 1.67 and 70% crystallinity (HA-2). Both HAs were implanted into a critical-size calvaria rat defects. RESULTS: To note, in the control group, the bone defects were filled with blood clot only. Descriptive and histomorphometric analyses after 1, 3, and 6 months postoperatively showed mild inflammatory infiltrate, mainly comprising macrophage-like and multinucleated giant cells, and an increase in the volume density of the fibrous tissues (

Caracterização físico-química de seis hidroxiapatitas comerciais para aplicações médico-odontológicas como material de enxerto

O objetivo desse trabalho foi caracterizar seis hidroxiapatitas granulares para aplicação em área médico-odontológica como material de enxerto. Estes materiais foram produzidos por quatro diferentes fabricantes e são todos facilmente disponíveis no mercado brasileiro. A caracterização físico-química foi realizada por meio de microscopia eletrônica de varredura, difração de raios-X, espectroscopia de infravermelho e área superficial específica (BET). Os resultados mostraram que apenas um dos produtos teve a caracterização perfeitamente de acordo com a especificação do fabricante. Os parâmetros de cristalinidade, área superficial e composição podem ser usados para estimar a biodegradabilidade da hidroxiapatita e como critério de controle de qualidade desses materiais.The aim of this work was to characterize six hydroxyapatites in granular form for applications in medicine and dentistry as bone graft and to compare with manufacturers' specification. These samples were produced by four different manufacturers, and all of them are easily available in the Brazilian market. Physicochemical characterization was carried out by using electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR) and surface area (BET) measurements. The results show that just one hydroxyapatite sample exhibited characterisitics in perfect agreement with the manufacturers' specifications. The studied parameters, namely crystallinity, surface area and composition may be used to estimate hydroxyapatite's biodegradability and as a criterion for quality control

Editorial nº 4: Capitalismo e racismo - a práxis negra

Editorial nº 4 of the Revista Fim do Mundo presenting the thematic dossier "Capitalism and racism - the black praxis".Editorial nº 4 de la revista Fim do Mundo presentando el dossier temático "Capitalismo y racismo - la praxis negra".Editorial nº 4 da Revista Fim do Mundo apresentando o dossiê temático "Capitalismo e racismo - a práxis negra"

Measurement of Vertical Profiles of the Atmospheric Surface Layer With Low-Cost Instrumentation on Board a Drone

Atmospheric natural disasters can have their damage mitigated if meteorological alerts are disseminated on time Among the ways to get data related to weather conditions are the use of atmospheric profilers and numerical models Such resources can be used for studies related to the surface layer which covers a range from 20 to 200 meters below the low troposphere In order to make atmospheric experiments achievable without great financial expenditure a low-cost atmospheric profiler was developed together with the Laboratory of Monitoring and Numerical Modeling of Climate Systems LAMMOC of the Federal Fluminense University UFF to be on board a drone and based on prototyping with Arduino which had as sensors the DHT22 for measuring temperature and relative humidity and the BMP280 for measuring atmospheric pressure Thus this profiler was used in an experiment from which atmospheric vertical profiles were generated and compared with profiles generated by the numerical model Weather Research and Forecasting WRF and post-processed by the WRF-Python routines package As a result it was noticed that the observed data profiles described a behavior of the surface layer that indicates the occurrence of thermal inversion and change of regime of this layer from the stable passing through the neutral to the unstable With this it is evaluated that the method of using this profiler can be applied in several atmospheric studies such as atmospheric pollution and nowcasting weather forecast as well as its potential for use in areas such as operational meteorology and assimilation of data from numerical models shows to be promisin

Hemoglobin Uptake by Paracoccidioides spp. Is Receptor-Mediated

Iron is essential for the proliferation of fungal pathogens during infection. The availability of iron is limited due to its association with host proteins. Fungal pathogens have evolved different mechanisms to acquire iron from host; however, little is known regarding how Paracoccidioides species incorporate and metabolize this ion. In this work, host iron sources that are used by Paracoccidioides spp. were investigated. Robust fungal growth in the presence of the iron-containing molecules hemin and hemoglobin was observed. Paracoccidioides spp. present hemolytic activity and have the ability to internalize a protoporphyrin ring. Using real-time PCR and nanoUPLC-MSE proteomic approaches, fungal growth in the presence of hemoglobin was shown to result in the positive regulation of transcripts that encode putative hemoglobin receptors, in addition to the induction of proteins that are required for amino acid metabolism and vacuolar protein degradation. In fact, one hemoglobin receptor ortholog, Rbt5, was identified as a surface GPI-anchored protein that recognized hemin, protoporphyrin and hemoglobin in vitro. Antisense RNA technology and Agrobacterium tumefaciensmediated transformation were used to generate mitotically stable Pbrbt5 mutants. The knockdown strain had a lower survival inside macrophages and in mouse spleen when compared with the parental strain, which suggested that Rbt5 could act as a virulence factor. In summary, our data indicate that Paracoccidioides spp. can use hemoglobin as an iron source most likely through receptor-mediated pathways that might be relevant for pathogenic mechanisms

Retenção prolongada de molares decíduos: relato de caso

Prolonged retention of a deciduous tooth is characterized by a common condition that occurs when the deciduous tooth surpasses its normal exfoliation time and remains in the oral cavity. The aim of this study is to report a clinical case of prolonged retention of a deciduous tooth. A 12-year-old female patient attended the Dental Clinic at CEUMA University, Imperatriz Campus, with the chief complaint of prolonged retention of deciduous teeth. After clinical and radiographic evaluation, surgical intervention of the deciduous teeth with prolonged retention was performed, followed by careful follow-up. Early diagnosis and intervention in cases of prolonged retention of deciduous molars are of paramount importance to minimize or prevent occlusion damage. In this regard, for children with prolonged retention of deciduous teeth, the proposed treatment may be surgical in order to prevent the impaction of the succeeding permanent teeth.A retenção prolongada de um dente decíduo é caracterizada por uma condição comum que ocorre quando o dente decíduo ultrapassa o seu tempo de esfoliação normal, e permanece na cavidade bucal. O objetivo deste trabalho é de relatar um caso clínico de retenção prolongada de um dente decíduo. Paciente de 12 anos de idade, sexo feminino compareceu à Clínica Odontológica da Universidade CEUMA, Campus de Imperatriz, com queixa principal de retenção prolongada dos dentes decíduos. Após avaliação clínica e radiográfica foi realizada intervenção cirúrgica dos dentes decíduos com retenção prolongada, seguida de um acompanhamento cuidadoso. O diagnóstico e a intervenção precoce em casos de retenção prolongada dos molares decíduos são de fundamental importância para minimizar ou evitar danos à oclusão. Nesse sentido, crianças com retenção prolongada de dentes decíduos, os tratamento proposto pode ser o cirúrgico, a fim de impedir a impactação dos dentes permamentes sucessores

Dendritic Cell Targeting Using a DNA Vaccine Induces Specific Antibodies and CD4+ T Cells to the Dengue Virus Envelope Protein Domain III

Dengue fever has become a global threat, causing millions of infections every year. An effective vaccine against all four serotypes of dengue virus (DENV) has not been developed yet. Among the different vaccination strategies available today, DNA vaccines are safe and practical, but currently induce relatively weak immune responses in humans. In order to improve immunogenicity, antigens may be targeted to dendritic cells (DCs), the main antigen presenting cells and orchestrators of the adaptive immune response, inducing T and B cell activation. It was previously shown that a DNA vaccine encoding a fusion protein comprised of an antigen and a single-chain Fv antibody (scFv) specific for the DC endocytic receptor DEC205 induced strong immune responses to the targeted antigen. In this work, we evaluate this strategy to improve the immunogenicity of dengue virus (DENV) proteins. Plasmids encoding the scFv αDEC205, or an isotype control (scFv ISO), fused to the DENV2 envelope protein domain III (EDIII) were generated, and EDIII specific immune responses were evaluated in immunized mice. BALB/c mice were intramuscularly (i.m.) immunized three times with plasmid DNAs encoding either scDEC-EDIII or scISO-EDIII followed by electroporation. Analyses of the antibody responses indicated that EDIII fusion with scFv targeting the DEC205 receptor significantly enhanced serum anti-EDIII IgG titers that inhibited DENV2 infection. Similarly, mice immunized with the scDEC-EDIII plasmid developed a robust CD4+ T cell response to the targeted antigen, allowing the identification of two linear epitopes recognized by the BALB/c haplotype. Taken together, these results indicate that targeting DENV2 EDIII protein to DCs using a DNA vaccine encoding the scFv αDEC205 improves both antibody and CD4+ T cell responses. This strategy opens perspectives for the use of DNA vaccines that encode antigens targeted to DCs as a strategy to increase immunogenicity

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio