Contribution of plant phytochemicals to organic homeostasis: focus on the aging process and opportunistic infections

Aging process is conceived as a normal stage during human life cycle, but it is also considered a hot topic among scientists and medical community. Alarming rates of premature aging and oxidative stress-related diseases have increasingly affect human individuals. Stress, pollution and exposition to chemical substances are considered the main triggering factors for those conditions; in addition, they also suppress the immune system and, therefore, improve organic vulnerability and occurrence of opportunistic infections [I]. Apart from the associated morbidity and mortality, the increasing rates of antimicrobial resistance improve the severity of the clinical conditions [2]. Botanical preparations possess a multitude of bioactive properties, namely acting as antimicrobials, antioxidants, and homeostasis modulators. Thus, upcoming alternatives, mainly based in plant phytochemicals, are necessary to improve the wellbeing as also life expectancy of individuals. The present study aims to evaluate and to compare both antioxidant and antimicrobial properties of plant extracts rich in phenolic compounds. Among the tested plants, Glycyrrhiza glabra L. (licorice) evidenced the most pronounced free radicals scavenging and antimicrobial effects, followed by Salvia officina/is L. (sage), Thymus vulgaris L. (thyme) and Origanum vulgare L. (oregano). Eucalyptus globulus Labill. (blue gum) and Juglans regia L. (walnut) also showed a high effect, while Pterospartum tridentatum (L.) Willk. (carqueja) and Rubus ulmifolius Schott (elm leaf blackberry) displayed moderate effects, and lastly, Tabebuia impetigirwsa (Mart. ex DC) Standley (pau d'arco), Foeniculum vulgare Miller (fennel), Rosa canina L. (rose hips) and Matricaria recutita L. (chamomile) gave only slight effects. In general, the most pronounced bioactivities were observed in the plant preparations (infusion>decoction>hydromethanolic extract) with higher levels of phenolic compounds (both flavonoids and phenolic acids). The observed synergisms between the phenolic compounds present in the extracts highlight the use of phytochemicals as future health promoters. However, further studies are necessary to understand the effective mode of action of individual phenolic constituents as also the existence of polyvalence relationships between them.

Contribution of plant-derived phenolic compounds to combat Candida species biofilms

Opportunistic fungal infections, namely involving Candida species, constitute a hot topic for scientific researchers. The present wor1( aims to access antifungal potential of plant-derived phenolic extrac:ls against planktonic cells and biofilms of Candida species. Eucalyptvs globulus Labill. (blue gum), Glycyrrhiza glabra L. (licorice), Juglans regia L. (walnut) and Salvia officina/is L. (sage) evidenced to be the most effective Candida growth inhibitors, using disc diffusion assay. Minmal inhibitory (MIC) and minimal fungicidal (MFC) concentrations, and chemical composition of extracts by using HPLC-DAO-ESVMS were also determined. Blue gum and walnut mainly exerted fungistatic potential, while sage exerted an interesting anti-Candida potential. However, the most prominent candidacidal potential was observed to licorice extract, being achieved the lowest MIC and MFC values. The candidacidal potential of these phenolic extracts was mainly attributed to their high abundance in flavonoids, mainly flavones: luteolin (sage) and apigen~ derivatives (licorice), and flavanones: liQuiritin derivatives (licorice). In order to deepen the knowledge on the most effective extract. its abiity to inhibit biofilm formation was evaluated. Overall, a double concentration of MFC value was necessary to achieve similar results in biofims. Row cytometry assays were also carried out, and the obtained results revealed that primary lesion of cellular membrane appear to be most relevant mode of action. Thus, plant derived phenolic compounds evidence a promising potential to combat Candida species biofilms, both individually or combined with conventional therapy.

INVESTIGATING THE USE OF MAZE-CBM FOR HIGH SCHOOL STUDENTS

Recent legislation and initiatives set forth high academic expectations for all high school graduates in the area of reading (National Governors Association Center for Best Practices, 2010; Every Student Succeeds Act, 2015). To determine which students need additional support to meet these reading standards, teachers can conduct universal screening using formative assessments. Maze Curriculum-Based Measurement (Maze-CBM) is a commonly used screening and progress monitoring assessment that the National Center on Intensive Intervention (2013) and the Center on Instruction (Torgesen & Miller, 2009) recommend. Despite the recommendation to use Maze-CBM, little research has been conducted on the reliability and validity of Maze-CBM for measuring reading ability for students at the secondary level (Mitchell & Wexler, 2016). In the papers included in this dissertation, I present an initial investigation into the use of Maze-CBM for secondary students. In the first paper, I investigated prior studies of Maze-CBM for students in Grades 6 through 12. Next, in the second paper, I investigated the alternate-form reliability and validity for screening students in Grades 9 and 10 using signal detection theory methods. In the third paper, I examined the effect of genre on Maze-CBM scores with a sample of students in Grades 9 and 10 using multilevel modeling. When writing these three papers, I discovered several important findings related to Maze-CBM. First, there are few studies that have investigated the technical adequacy of Maze-CBM for screening and progress monitoring students in Grades 6 through 12. Additionally, only two studies (McMaster, Wayman, & Cao, 2006; Pierce, McMaster, & Deno, 2010) examined the technical adequacy of Maze-CBM for high school students. A second finding is that the reliability of Maze-CBM is often below acceptable levels for making screening decisions or progress monitoring decisions (.80 and above and .90 and above, respectively; Salvia, Ysseldyke, & Bolt, 2007) for secondary students. A third finding is that Maze-CBM scores show promise of being a valid screening tool for reading ability of secondary students. Finally, I found that the genre of the text used in the Maze-CBM assessment does impact scores on Maze-CBM for students in Grades 9 and 10.

Meios de transporte de dentes avulsionados

A avulsão dentária é um dos mais severos traumatismos dento-alveolares, caracterizado pela desinserção completa do dente do seu ambiente natural, o alvéolo. O prognóstico desta condição traumática depende em grande escala da atitude adoptada no momento do acidente. No entanto, quando o reposicionamento dentário imediato não é possível, factores como o tempo que o dente permaneceu no meio extra-oral e o meio de transporte utilizado influenciam consideravelmente o prognóstico da peça dentária avulsionada. A elaboração deste trabalho tem como objectivo verificar o estado actual da investigação científica relativamente aos meios de transporte de dentes avulsionados, nomeadamente, indagar sobre os potenciais meios de transporte actualmente em estudo. Foi efectuada uma pesquisa bibliográfica digital, na base de dados PUBMED, com os seguintes termos de pesquisa: “tooth avulsion”, “storage media”, “tooth reimplantation” e “delayed reimplantation” isoladamente ou em combinação. Para a selecção dos artigos foram estipulados critérios de inclusão e exclusão na pesquisa bibliográfica. Existem soluções especificamente concebidas para a conservação e preservação de células humanas, que idealmente deveriam ser sempre utilizadas como meios de transporte de dentes avulsionados, tais como: solução balanceada de Hank, Viaspan®, Eurocollins® e determinados meios de cultura. São soluções que apresentam propriedades biofísico-químicas que os levam a ser considerados meios de transporte de eleição. No entanto, a sua escassa disponibilidade no momento da avulsão desperta a necessidade pela investigação de outros meios, nomeadamente, soluções que apresentem nesse contexto maior disponibilidade. O leite, a saliva, a solução salina e o Gatorade® continuam a representar meios alternativos para o transporte de dentes avulsionados, porém, outras soluções emergentes apresentam características biológicas que as remetem para meios de transporte promissores como por exemplo: solução de propólis, o chá verde, o extracto de aloe Vera, água de côco, clara de ovo, extracto de amora, sumo de romã, salvia officinalis e Ricetral®. Evidencia-se, com este trabalho, a necessidade de estudos futuros nesta área de modo a que meios de transporte que actualmente pensa-se poderem ser extremamente efectivos na manutenção da viabilidade célular e com ampla disponibilidade, possam ser utilizados de forma segura e vantajosa para o paciente, nomeadamente, garantindo melhores prognósticos em situações de reimplantação dentária.