A Bioguided Approach for the Screening of Antibacterial Compounds Isolated From the Hydroalcoholic Extract of the Native Brazilian Bee's Propolis Using Mollicutes as a Model.

Nature is a vast source of medicinal substances, including propolis, which has been extensively investigated. Propolis is a resinous substance produced by bees from the exudates of plants that they collect and modify in their jaws; it is a rich and complex matrix with secondary metabolites of diverse botanical origins. The objective of this study was to apply an in vitro bioguided approach using as a model system the mollicutes with a sample of propolis from the Brazilian native bee Melipona quadrifasciata (mandaçaia) in order to identify potential new molecules with antimicrobial activity. A crude hydroalcoholic extract was obtained and submitted to liquid-liquid partitioning with solvents of different polarities, generating four different fractions: aqueous, dichloromethane, butanol, and ethyl acetate fractions. The antimollicute activity assays served as a basis for the bioguided fractionation. The dichloromethane fraction was the most promising, exhibiting a minimal inhibitory concentration (MIC) of 125 µg/mL against Mycoplasma pneumoniae. After purification by column liquid chromatography, a subfraction presenting MIC of 15.6 µg/mL against Mycoplasma genitalium was highlighted. The fractions were also tested against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Using gas chromatography coupled to a mass spectrometer (GC-MS), several volatile compounds were identified in the non-polar fractions of this propolis. However, the more purified molecules had no better antimollicute activity than their original subfraction. Apparently, the synergism among its compounds is largely responsible for the antibacterial activity of the propolis of this native Brazilian bee.

Longitudinal analysis of laboratory tests in a population-based study / Análise longitudinal da qualidade dos exames laboratoriais em um estudo de base populacional

ABSTRACT Clinical laboratories must have quality management systems that guarantee the reliability of their results. Furthermore, in longitudinal studies, it is important that the generated data be analyzed over time, as an additional measure of quality control (QC), seeking to identify fluctuations not explainable by biological variables. Applying this strategy to the SHIP-Brazil study was the aim of this work. Thus, we analyzed the results of fasting glucose, post-load glucose and glycated hemoglobin in the participants of the SHIP-Brazil study, from July 2014 to November 2016, in relation to the following aspects: difference of each individual's results from the mean of the month over time, mean and median of results over time, and percentage of results above the reference values over time, with trend line. According to the observed data, in order to guarantee the correct association of laboratory parameters with different health and disease conditions, the fasting blood glucose and post-load glucose measurements in the samples collected during the first months of the study are consistent, despite being performed in two different facilities. This QC strategy has proved very useful, and may even be used by clinical laboratories in their routine, observing result fluctuations of their population in the course of time, being capable of eventually detect bias even before the routine practices of internal and external quality control.

RESUMEN Los laboratorios clínicos deben tener sistemas de gestión de calidad que garanticen la fiabilidad de los resultados. Además, en estudios longitudinales, es importante que los datos generados sean analizados a lo largo del tempo, como medida adicional de control de calidad (QC), buscando identificar fluctuaciones no explicables por variables biológicas. Aplicar esa estrategia al estudio SHIP-Brasil es el objetivo de este trabajo. Analizamos los resultados de glucemia en ayunas, prueba de sobrecarga de glucosa y hemoglobina glucada en los participantes del estudio SHIP-Brasil, en el período de julio de 2014 a noviembre de 2016, acerca de los siguientes aspectos: diferencia de los resultados de cada individuo con respecto a la media del mes con el tiempo; media y mediana de los valores con el tiempo; y porcentaje de resultados por encima de los valores de referencia con el tempo, con línea de tendencia. Según los datos observados, las mediciones de glucemia en ayunas y tras una sobrecarga de glucosa, en las muestras recolectadas en los primeros meses de estudio, resultan consistentes, a pesar de haber sido realizadas en dos laboratorios distintos. Esa estrategia de QC se presentó muy útil y puede, incluso, ser utilizada por laboratorios clínicos en su rutina, observando fluctuaciones de resultados de su población a lo largo del tiempo, detectando, eventualmente, desviaciones aún antes de las prácticas rutinarias de control interno y externo de calidad.

RESUMO Os laboratórios clínicos devem ter sistemas de gestão da qualidade que garantam a fidedignidade dos resultados. Ainda, em estudos longitudinais, é importante que os dados gerados sejam analisados ao longo do tempo, como medida adicional de controle de qualidade (CQ), buscando identificar flutuações não explicáveis por variáveis biológicas. Aplicar essa estratégia ao estudo SHIP-Brasil foi o objetivo deste trabalho. Analisamos os resultados de glicemia em jejum, glicemia pós-sobrecarga e hemoglobina glicada nos participantes do estudo SHIP-Brasil, no período de julho de 2014 a novembro de 2016, em relação aos seguintes aspectos: diferença dos resultados de cada indivíduo em relação à média do mês ao longo do tempo; média e mediana dos valores ao longo do tempo; e porcentagem de resultados acima dos valores de referência ao longo do tempo, com linha de tendência. De acordo com os dados observados, as dosagens de glicemia em jejum e glicemia pós-sobrecarga, nas amostras coletadas nos primeiros meses de estudo, apresentam-se consistentes, mesmo tendo sido realizadas em dois laboratórios distintos. Essa estratégia de CQ mostrou-se bastante útil e pode, inclusive, ser utilizada pelos laboratórios clínicos em sua rotina, observando as flutuações de resultados de sua população ao longo do tempo, detectando, eventualmente, desvios antes mesmo das práticas rotineiras de controle interno e externo da qualidade.

Chemical composition and evaluation of the antimicrobial activity of the essential oil from leaves of Eugenia platysema.

This study describes the qualitative and quantitative chemical composition and evaluates the antibacterial activity of essential oil from Eugenia platysema leaves. Analysis by GC-FID and GC-MS allowed the identification of 22 compounds. Different from the other species of the Eugenia genus, the major compound found in the essential oil was the diterpene phytol (66.05%), being this the first report of the presence of this compound in the essential oils from Eugenia genus. The sesquiterpene elixene was the second most concentrated compound in the studied essential oil (9.16%). The essential oil from E. platysema was tested for its antibacterial activity against cell-walled bacteria and mollicute strains of clinical interest using the microdilution broth assay. The results showed that the essential oil of E. platysema was inactive until 1000 µg mL(-1) against tested bacteria.

Evaluation of seasonal chemical composition, antibacterial, antioxidant and anticholinesterase activity of essential oil from Eugenia brasiliensis Lam.

This study describes the seasonal composition and the antibacterial, antioxidant and anticholinesterase activity of the essential oil from Eugenia brasiliensis leaves. Analysis by using GC allowed the identification of 40 compounds. It was observed that the monoterpenes varied more (42%) than the sesquiterpenes (14%), and that the monoterpene hydrocarbons suffered the greatest variation throughout the year (64%). Major compounds were spathulenol in the spring (16.02 ± 0.44%) and summer (18.17 ± 0.41%), τ-cadinol in the autumn (12.83 ± 0.03%) and α-pinene (15.94 ± 0.58%) in the winter. Essential oils were tested for their antibacterial activity, and the best result was obtained from the autumn oil, with MIC = 500 µg mL(- 1) against Staphylococcus saprophyticus and Pseudomonas aeruginosa. Antioxidant activity was evaluated using DPPH, lipid peroxidation and iron-reducing power assays, as well as the anticholinesterase activity. Both tests showed a weak performance of the essential oils.

Determinação das glicemias capilar e venosa com glicosímetro versus dosagem laboratorial da glicose plasmática / Determination of capillary blood glucose and venous blood glucose with a glucometer versus laboratory determination of venous plasma glucose

INTRODUÇÃO E OBJETIVOS: Diabetes mellitus (DM) é a mais importante patologia que envolve o pâncreas endócrino, sendo uma das principais causas de morbidade e mortalidade na população geral. O objetivo deste trabalho foi avaliar a determinação da glicemia em diferentes tipos de amostras e metodologias. MÉTODOS: Utilizando um equipamento Accu-Check Advantage (Roche), foi avaliada a glicemia em amostras de sangue capilar (GCG) e de sangue venoso (GVG), e a dosagem da glicemia venosa em plasma (GVE) foi realizada por método enzimático de rotina. RESULTADOS E CONCLUSÃO: Foi observada boa correlação entre a GCG e a GVG (r = 0,8742). Entretanto, houve diferença significativa entre a GCG e a GVE (r = 0,6543) e entre a GVG e a GVE (r = 0,5038) (p < 0,001). Essa diferença é maior considerando-se apenas os pacientes normoglicêmicos. O fato de haver diferentes estudos com resultados conflitantes entre si não depende somente da marca ou série específica do glicosímetro, já que uma mesma marca pode apresentar resultados inconsistentes em diferentes estudos.

INTRODUCTION AND OBJECTIVES: Diabetes mellitus is the most important pathology that affects the endocrine pancreas and one of the main causes of morbidity and mortality among the general population. The aim of this work was to evaluate the correlation of blood glucose determination in different types of samples and methodologies. METHODS: Using an Accu-Check Advantage glucometer (Roche), it was determined the blood glucose levels in capillary (CBG) and venous (VBG) samples, and plasma venous glucose was determined by routine enzymatic methodology (EVG). RESULTS AND CONCLUSION: It was observed a good correlation between CBG and VBG (r = 0.8742). However, there was a significant difference between CBG and EVG (r = 0.6543) and between VBG and EVG (r = 0.5038) (p < 0.001). These differences are even more substantial considering only normoglycemic patients. The existence of different studies with inconsistent results does not depend only on the glucometer brand or its specific series, as the same device may present inconsistent results in different studies.