Ionic trace elements such as Mg2+, Mn2+ and Sr2+ are very difficult to stabilize in the hydroxyapatite lattice, and they can induce phase transformations when subjected to thermal treatments. The effects of the ions themselves are often confused with the effects of the newly formed phases. Therefore, the objective of this work was to evaluate the effects of the ions isolated from the effects caused by the inherent phase transformations observed in these systems. WDXRF, XRD, FTIR and biological assays using mouse preosteoblastic cells (MC3T3-E1) showed the Mg2+ ions can stimulate cell differentiation even when segregated from the HA structure in the form of MgO. However, the presence of MgO considerably retards cell proliferation. At the same time, Mn2+ ions are able to increase cell proliferation and induce the production of high levels of ALP, regardless of whether they are inserted into the HA structure or segregated in the form of Mn3O4. Finally, the presence of Sr2+ in the HA lattice does not appear to directly affect cell behavior, since both the proliferation and production of ALP are comparable to those observed in the nondoped HA sample.

Abstract INTRODUCTION: Considering that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in feces, this study aimed to verify a possible relationship between basic sanitation indices and coronavirus disease (COVID-19) numbers/rates. METHODS: Data of COVID-19 cases registered in Brazil until May 28, 2020, and independent variables associated with basic sanitation were analyzed. RESULTS: A significant correlation between the number of cases and sewage treatment index/population density was observed. In addition, COVID-19 incidence and mortality rates were significantly associated with the total water service index and lethality rate was significantly associated with the sewage treatment index. CONCLUSIONS: Precarious basic sanitation infrastructure may potentially increase the SARS-CoV-2 transmission in Brazil.

Introdução:O gene TP53 (proteína tumoral p53) é alvo constante de investigação na patogênese do câncer. A imuno-histoquímica fornece dados limitados na análise de p53 no processo da carcinogênese bucal e o sequenciamento de TP53 pode contribuir nessa investigação. Contudo, a obtenção de ácido desoxirribonucleico (DNA) com qualidade para amplificação e livre de contaminação pode constituir uma tarefa difícil na utilização de material parafinado.Objetivo:Padronizar as técnicas de extração de DNA, amplificação por reação em cadeia da polimerase (PCR) e sequenciamento para a análise de mutações em TP53.Material e métodos:Foram selecionados 39 casos de carcinomas de células escamosas bucal da Divisão de Patologia do Instituto Nacional de Câncer (Inca). O DNA foi extraído utilizando o sistema comercial QIAamp® DNA minikit®. Após quantificação do DNA por espectrofotometria, 250 ng de amostra foram amplificados pela técnica de PCR para o éxon 2 e por nested PCR para o éxon 6 do gene TP53. Da amostra total, 11 casos foram selecionados para a padronização da reação de sequenciamento do éxon 2.Resultados:As amostras de DNA apresentaram concentração média de 119,74 ng/µl ± 88,86 (28,9-556,4 ng/µl) e pureza de 1,69 ± 0,18 (1-1,9). Do total das amostras analisadas, 33 (84,6%) foram amplificadas para o éxon 2, e todas (39/100%), para o éxon 6. No sequenciamento do éxon 2 obtiveram-se sequências passíveis de leitura em 10 (90,9%) casos.Conclusão:A otimização das condições para o sequenciamento de TP53 foi obtida, o que facilitará a análise de mutações em tecidos parafinados, permitindo a realização de estudos moleculares retrospectivos.

Introduction:The tumor protein p53 gene (TP53) is a constant target of investigation in cancer pathogenesis. Analysis by immunohistochemistry provides limited data about p53 in oral carcinogenesis, and TP53sequencing can contribute to this analysis. However, obtaining high-quality and contamination-free deoxyribonucleic acid (DNA) for a proper amplification can be a difficult task when using paraffin-embedded tissues.Objective:Standardize DNA extraction, polymerase chain reaction (PCR) amplification and DNA sequencing techniques for TP53 mutation analysis.Material and methods:Thirty-nine cases of oral squamous cell carcinoma (OSCC) were selected from the Pathology Division of Instituto Nacional de Câncer (Inca). The DNA extraction method used was the QIAamp® DNA minikit® system. After DNA quantification by spectrophotometry, 250 ng of genetic material obtained from TP53 gene were amplified by PCR for exon 2 and by nested PCR for exon 6. Out of the total sample, 11 cases were selected for exon 2 sequencing. Results: The DNA samples presented mean concentration of 119.74 ± 88.86 ng/µl (28.9-556.4) and purity of 1.69 ± 0.18 (1-1.9). Thirty-three (84.6%) samples were amplified for exon 2, and all samples for exon 6 (39/100%). Readable sequencing data were obtained in 10 (90.9%) cases.Conclusion:Optimization of conditions for TP53 sequencing was obtained, and this will facilitate the analysis of mutations in paraffin-embedded tissues, allowing molecular retrospective studies.

Objective The aim of this study was to produce dense granules of tricalcium phosphate (β-TCP) and magnesium (Mg) substituted β-TCP, also known as β-TCMP (Mg/Ca=0.15 mol), in order to evaluate the impact of Mg incorporation on the physicochemical parameters and in vitro biocompatibility of this novel material. Material and Methods The materials were characterized using X-ray diffraction (XRD), infrared spectroscopy (FTIR), electron microscopy and inductively coupled plasma (ICP). Biocompatibility was assayed according to ISO 10993-12:2007 and 7405:2008, by two different tests of cell survival and integrity (XTT and CVDE). Results The XRD profile presented the main peaks of β-TCP (JCPDS 090169) and β-TCMP (JCPDS 130404). The characteristic absorption bands of TCP were also identified by FTIR. The ICP results of β-TCMP granules extract showed a precipitation of calcium and release of Mg into the culture medium. Regarding the cytotoxicity assays, β-TCMP dense granules did not significantly affect the mitochondrial activity and relative cell density in relation to β-TCP dense granules, despite the release of Mg from granules into the cell culture medium. Conclusion β-TCMP granules were successfully produced and were able to release Mg into media without cytotoxicity, indicating the suitability of this promising material for further biological studies on its adequacy for bone therapy.

The aim of this work was to produce hydroxyapatite (HA) granules containing 0, 0.5, 1 and 5 mol. (%) of strontium (Sr), evaluate the physico-chemical properties and also the cytotoxicity by three different parameters of cell viability (ISO 10993-5, 10993-12). The physico-chemical characterization was carried out by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and X-ray fluorescence (XRF). The XRD profile presented the main peaks of HA (JCPDS 860740) and the absorption bands of HA were identified by FTIR. The XRF results showed that the strontium concentration was close to the theoretical value. Regarding the cytotoxicity assays, the incorporation of strontium up to 5 mol. (%) to the HA did not affected dehydrogenase activity (XTT, 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide), membrane integrity (neutral red uptake) or DNA contend (incorporation of crystal violet), in relation to HA alone. In conclusion, hydroxyapatite containing from 0.5 to 5 mol. (%) of Sr was successfully produced and presented no cytotoxicity.

Oral hairy leukoplakia (OHL) is generally reported in patients with severe immunosuppression, except for a few cases in individuals with moderate degree of immunodeficiency. It is a white lesion that appears mainly in the lateral border of the tongue, caused by Epstein-Barr virus (EBV). The nuclear changes caused by EBV (Cowdry A inclusion, ground glass and nuclear beading), observed in cytopathology, are specific and enough for the definitive diagnosis of OHL, independent of the identification of the virus. Here we investigated the prevalence of OHL and the presence of EBV-DNA in the lateral borders of the tongue from 90 pregnant women, 90 diabetes mellitus (DM) patients, 30 healthy individuals (negative group) and 30 HIV+ with OHL (positive group). Smears were analyzed by cytopathology and polymerase chain reaction (PCR). A case of subclinical OHL and candidiasis was identificated in a DM patient by cytopathologic analysis. PCR results demonstrated EBV-DNA in 65% of the pregnant women, in 35% of DM patients, and in 20% of the healthy individuals. We concluded that DM patients can develop OHL with a low prevalence. Furthermore, the prevalence of the EBV in lateral border of the tongue is larger in pregnant women than in healthy individuals.