Ultrastructural changes of collagen and elastin in human gingiva during orthodontic tooth movement

After 15 days of mesializing or distalizing orthodontic treatment, 10 permanent premolars of young patients were extracted with the interdental gingiva. The connective tissues of the compressed or stretched interdental papillae were compared to that of untreated samples by light and transmission electron microscope.Large collagen fibres bundles represented by fibrils with a banding pattern of 64 nm and a mean diameter of 75 nm were observed in compressed interdental gingiva. Several elastic fibres with a mean diameter of 950 nm were also present. In some central areas of compressed gingiva collagen fibrils longitudinally split into widely spaced microfibrils were often observed in proximity to the elastic fibres.In stretched and untreated interdental papillae the collagen fibrils presented a mean diameter of 66 nm and 57 nm respectively. In both groups, few elastic fibres ranging in diameter 600 nm were seen. The increased size of the gingival collagen fibrils undergoing pressure and tension is indicative of remodelling of the fibrous collagen system.The fair increase in number and size of elastic fibres in compressed gingiva suggests that the elastic fibre system takes over the place whenever a collapse of the collagenous framework occurs.Après 15 jours de traitement orthodontique par mésialisation ou distalisation, 10 prémolaires permanentes ont été extraites chez de jeunes patients, ainsi que la gencive interdentaire adjacente. Le tissu conjonctif des papilles interdentaires comprimées ou étirées a été comparé avec celui d’échantillons de dents n’ayant pas subi de traitement. L’observation a été faite en microscopie classique et en microscopie électronique à transmission. Dans la gencive interdentaire comprimée, on observe de longs faisceaux de fibres de collagène faits de fibrilles qui présentent une périodicité de 64 nm et un diamètre inférieur à 75 nm. Ont été observées également de fibres élastiques d’une diamètre inférieur à 950 nm. Dans certaines zones centrales de gencive comprimée, on peut voir, à proximité dess fibres élastiques, des fibrilles de collagène réparties longitudinalement en microfibrilles très espacées.Dans la gencive interdentaire étirée et dans celle non soumise au traitement orthodontique, les fibrilles de collagène présentent un diamètre de 66 nm et 57 nm respectivement. Dans ces deux groupes, on note un très petit nombre de fibres élastiques de 600 nm de diamètre. L’augmentation du nombre et de la taille des fibres élastiques dans la gencive comprimée indique que le système de fibres élastiques remplace la trame collagène qui a subi un collapsus

Polycyclic Aromatic Hydrocarbon-degrading Bacteria from Aviation Fuel Spill Site at Ibeno, Nigeria

Polycyclic aromatic hydrocarbon (PAH)–degrading bacteria were isolated from aviation fuel contaminated soil at Inua Eyet Ikot in Ibeno, Nigeria. PAH-degrading bacteria in the contaminated soil were isolated by enrichment culture technique. Isolates with high PAH degrading potential characterized by their extensive growth on PAH-supplemented minimal salt medium were screened for their naphthalene, phenanthrene and chrysene degradability. The screening medium which contained selected PAHs as the sole source of carbon and energy showed that Micrococcus varians AFS-2, Pseudomonas putida AFS-3 and Alcaligenes faecalis AFS-5 exhibited a concentration–dependent growth in all the PAH–compounds tested. There were visible changes in the color of growth medium suggesting the production of different metabolites. Their acclimation to different PAH substrates was also evident as A. faecalis AFS-5 isolated from chrysene grew well on other less complex aromatic compounds. The isolate exhibited best growth (0.44 OD600) when exposed to 10 ppm of chrysene for 5 days and could utilize up to 90 ppm of chrysene. This isolate and others with strong PAH-degrading potentials are recommended for bioremediation of PAHs in aviation fuel-contaminated sites in the tropics

Synthetic Peptides Mimic gp75 from Paracoccidioides brasiliensis in the Diagnosis of Paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease, endemic in Latin America, caused by the thermal dimorphic fungus Paracoccidioides brasiliensis. Although some fungal antigens have already been characterized and used for serological diagnosis, cross-reactions have been frequently observed. Thus, the examination of fungal forms in clinical specimens or isolation of P. brasiliensis by culture is still the most frequent method for the diagnosis of this mycosis. In this study, a random peptide phage display library was used to select mimotopes of P. brasiliensis, which were employed as antigens in an indirect enzyme-linked immunosorbent assay. The protective monoclonal antibody against experimental PCM (anti-gp75) was used as molecular target to screen a phage display library. That approach led to a synthetic peptide named P2, which was synthesized and tested against PCM patients’ sera to check whether it was recognized. There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera. Sera from treated PCM group, patients with other mycosis or co-infected with HIV had much lower recognition of P2 than untreated patient group. The test showed a sensitivity of 100 and 94.59% of specificity in relation to human sera control. These data indicate a potential use of P2 as diagnostic tool in PCM. Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost

Raccomandazioni per l\u2019esecuzione della Curva Standard da Carico Orale di Glucosio (OGTT) per la diagnosi di Diabete Mellito

The Oral Glucose Tolerance Test (OGTT) is a fractional method which measures the body's ability to metabolize glucose. Despite its large-scale use, the OGTT is still not appropriately performed in most of the Italian laboratories, as proven by our previous recent survey. In particular, we have provided evidence for the variability for execution of the OGTT in Italian laboratories indicating a poor tendency to standardise the procedures and the methodologies. These findings have been a stimulus to promote an effective Nationwide educational campaign, in order to standardise the procedures for the diagnosis of altered glucose metabolism and diabetes. The present document reports therefore the recommendations concerning the OGTT performed for the classification of diabetes. These recommendations do not apply to the execution of the OGTT during pregnancy for diagnosing gestational diabetes mellitus

Aplicação de protótipo de microscópio de baixo custo como estratégia para o ensino de ciências e conscientização ambiental

Practical science classes are important methodological resources for teaching-learning process. However, many Brazilian public schools have poor laboratory structure, which hampers the development of practical activities. This extension project aimed to report the development of an interdisciplinary pedagogical strategy covering contents of biology, optics and environmental education, through the construction and application of a microscope prototype, made with low-cost and reusable electro-electronic materials. One hundred and twenty-six students from public elementary schools participated in the project. Workshops were held with theoretical and dynamic classes covering: i) a theoretical and dynamic class addressing concepts about cell, microscope physics and environmental education (solid and electro-electronic waste, recycling and reuse of waste, separation, and accountability), ii) a practical activity with the construction of a microscope prototype with recycled and reusable electronics and iii) evaluative questionnaire. The activity was based on the Sustainable Development Goals (SDGs - ONU), aiming at a quality education and responsible consumption and production. Besides, it was based on the concept of observation and experimentation as a didactic strategy for assimilating information. The results indicated an improvement in the students’ understanding of the concepts of waste and cell, as well as the operation of a microscope, confirming that the activity improved the teaching-learning process. The low cost and easy operable prototype can improve the infrastructure of the schools, besides being an interesting tool to distance education.Aulas práticas de ciências são importantes recursos metodológicos no processo ensino-aprendizagem dos alunos. No entanto, muitas escolas públicas brasileiras possuem escassa estrutura laboratorial, o que dificulta o desenvolvimento de atividades práticas. Este projeto de extensão teve como objetivo relatar o desenvolvimento de uma estratégia pedagógica interdisciplinar, abrangendo diversas áreas no ensino de Ciências, como conceitos de educação ambiental, citologia e óptica, por meio da construção e aplicação de um protótipo de microscópio, confeccionado com materiais eletroeletrônicos reutilizáveis, e outros de baixo custo. Participaram do projeto cento e vinte seis alunos, de escolas públicas do ensino fundamental. Foram ministradas oficinas compostas por: a) aula teórica e dinâmica abordando conceitos sobre a célula, física do microscópio e educação ambiental (resíduos sólidos e eletroeletrônicos, reciclagem e reutilização de resíduos, separação e responsabilização), b) aula prática com construção de protótipo de microscópio e c) questionário avaliativo. A atividade foi fundamentada nos Objetivos de Desenvolvimento Sustentável (ODS - ONU), visando à educação de qualidade e consumo e produção responsáveis, assim como na observação e experimentação como estratégia didática para a obtenção e assimilação de informações. Os resultados indicaram melhora na compreensão, por parte dos estudantes, de conceitos relacionados aos resíduos, células e funcionamento de um microscópio, confirmando a contribuição da atividade na melhoria do processo ensino–aprendizagem de ciências e conscientização ambiental. O protótipo, por ser de baixo custo e de fácil operação, pode aprimorar a infraestrutura de ensino das escolas, além de ser uma ferramenta interessante para auxiliar no ensino à distância