2,069 research outputs found
Effect of Kramecyne on the Inflammatory Response in Lipopolysaccharide-Stimulated Peritoneal Macrophages
Kramecyne is a new peroxide, it was isolated from Krameria cytisoides, methanol extract, and this plant was mostly found in North and South America. This compound showed potent anti-inflammatory activity; however, the mechanisms by which this compound exerts its anti-inflammatory effect are not well understood. In this study, we examined the effects of kramecyne on inflammatory responses in mouse lipopolysaccharide- (LPS-) induced peritoneal macrophages. Our findings indicate that kramecyne inhibits LPS-induced production of tumor necrosis factor (TNF-α) and interleukin- (IL-) 6. During the inflammatory process, levels of cyclooxygenase- (COX-) 2, nitric oxide synthase (iNOS), and nitric oxide (NO) increased in mouse peritoneal macrophages; however, kramecyne suppressed them significantly. These results provide novel insights into the anti-inflammatory actions and support its potential use in the treatment of inflammatory diseases
Mining for Restriction Endonucleases in Nicaragua
The Molecular Biology Center at the University of Central America in Nicaragua (CBM-UCA) was founded in 1999 to strengthen biotechnology research capacity and education in Nicaragua and the Central American region. One of the first projects launched by the CBM-UCA was bio-prospecting for key industrial enzymes. This ongoing study seeks to discover and characterize restriction enzymes (RE) in bacteria, and to create a database of microorganisms isolated and identified by 16S rDNA sequencing methodology. In this paper we highlight the importance of studying
the extreme environmental conditions for building knowledge of Nicaraguan biodiversity through modern molecular biology techniques such as metagenomics. The isolation of prototype enzymes such as EcoRV and ClaI is presented as an update and extension of previously undertaken work
Genotoxic and Cytotoxic Studies of Beta-Sitosterol and Pteropodine in Mouse
Beta-sitosterol (BS) and pteropodine (PT) are constituents of various plants with pharmacological activities potentially useful to man. The chemicals themselves possess biomedical properties related to the modulation of the immune and the nervous systems, as well as to the inflammatory process. Therefore, safety evaluation of the compounds is necessary in regard to their probable beneficial use in human health. The present study evaluates their genotoxic and cytotoxic potential by determining the capacity of the compounds to induce sister chromatid exchanges (SCE), or to alter cellular proliferation kinetics (CPK) and the mitotic index (MI) in mouse bone marrow cells. Besides, it also determines their capacity to increase the rate of micronucleated polychromatic erythrocytes (MNPE) in peripheral mouse blood, and the relationship polychromatic erythrocytes/normochromatic erythrocytes (PE/NE) as an index of cytotoxicity. For the first assay, four doses of each compound were tested: 200, 400, 600, and 1000 mg/kg in case of BS, and 100, 200, 300, and 600 mg/kg for PT. The results in regard to both agents showed no SCE increase induced by any of the tested doses, as well as no alteration in the CPK, or in the MI. With respect to the second assay, the results obtained with the two agents were also negative for both the MNPE and the PE/NE index along the daily evaluation made for four days. In the present study, the highest tested dose corresponded to 80% of the LD(50) obtained for BS and to 78% in the case of PT. The results obtained establish that the studied agents have neither genotoxic nor cytotoxic effect on the model used, and therefore they encourage studies on their pharmacological properties
How bias-correction can improve air quality forecast over Portugal
Currently three air quality modelling systems operate routinely with high-resolution over mainland Portugal for forecasting purposes, namely MM5-CHIMERE, MM5-EURAD, and CALIOPE. They each operate daily using different horizontal resolutions (10 km × 10 km, 5 km × 5 km, and 4 km × 4 km, respectively), specific physical and chemical parameterizations, and their own emission pre-processors (with a common EMEP emission database source but different spatial disaggregation methodologies). The operational BSC-DREAM8b model is coupled offline within the aforementioned air quality systems to provide the Saharan dust contribution to particulate matter. Bias-correction studies have demonstrated the benefit of using past observational data to reduce systematic model forecast errors. The present contribution aims to evaluate the application of two bias-correction techniques, the multiplicative ratio and the Kalman filter, in order to improve air quality forecasts for Portugal. Both techniques are applied to the three modelling systems over the full year of 2010. Raw and unbiased model results for the main atmospheric pollutants (O3, NO2, SO2, PM10, and PM2.5) are analysed and compared with data from 18 monitoring stations distributed within inland Portugal on an hourly basis. Statistical analysis shows that both bias-correction techniques improve the raw forecast skills (for all the modelling systems and pollutants). In the case of O3 max-8 h, correlation coefficients improve by 19-45%, from 0.56-0.81 (raw models) to 0.78-0.86 (corrected models). PM2.5 also presents significant improvements, for example correlation coefficients increase by more than 50% (with both techniques), reaching values between 0.50 and 0.64. The corrected primary pollutants NO2 and SO2 demonstrate significant relative improvements compared to O3, mostly because the original modelling system skills are lower for those species. Although the applied techniques have different mathematical formulations and complexity levels, there are comparable answers for all of the forecasting systems. Analysis performed over specific situations such as air quality episodes and cases of unvalidated or missing data reveals different behaviours of the bias-correction techniques under study. The results confirm the advantage of the application of bias-correction techniques for air quality forecasts. Both techniques can be applied routinely in operational forecast systems and they will be useful to provide accurate alerts about exceedances to the population
Clinical Relevance of Medicinal Plants and Foods of Vegetal Origin on the Activity of Cytochrome P450
Drug metabolism is a pharmacokinetic process whose main objective is to modify the chemical structure of drugs to easily excretable compounds. This process is carried out through phase I and phase II reactions. The enzymes of cytochrome P450 (CYP450) participate in phase I reactions, and their activity can be inhibited or induced by xenobiotics. The aim of this chapter is to study the clinical relevance of the induction and inhibition of CYP450, by describing the effect that some bioactive compounds present in medicinal plants or foods can modify, either increasing or decreasing the activity of CYP450 enzymes and with it modify the bioavailability and depuration of drugs. Examples will be described on the interaction of medicinal plants and foods of vegetal origin that when combined with some drugs can generate toxicity or therapeutic failure; this will allow gathering relevant information on the adequate pharmacological management in different clinical situations
At the tip of an iceberg: citizen science and active surveillance collaborating to broaden the known distribution of Aedes japonicus in Spain
Background: Active surveillance aimed at the early detection of invasive mosquito species is usually focused on seaports and airports as points of entry, and along road networks as dispersion paths. In a number of cases, however, the first detections of colonizing populations are made by citizens, either because the species has already moved beyond the implemented active surveillance sites or because there is no surveillance in place. This was the case of the first detection in 2018 of the Asian bush mosquito, Aedes japonicus, in Asturias (northern Spain) by the citizen science platform Mosquito Alert. Methods: The collaboration between Mosquito Alert, the Ministry of Health, local authorities and academic researchers resulted in a multi-source surveillance combining active field sampling with broader temporal and spatial citizen-sourced data, resulting in a more flexible and efficient surveillance strategy. Results: Between 2018 and 2020, the joint efforts of administrative bodies, academic teams and citizen-sourced data led to the discovery of this species in northern regions of Spain such as Cantabria and the Basque Country. This raised the estimated area of occurrence of Ae. japonicus from < 900 km2 in 2018 to > 7000 km2 in 2020. Conclusions: This population cluster is geographically isolated from any other population in Europe, which raises questions about its origin, path of introduction and dispersal means, while also highlighting the need to enhance surveillance systems by closely combining crowd-sourced surveillance with public health and mosquito control agencies’ efforts, from local to continental scales. This multi-actor approach for surveillance (either passive and active) shows high potential efficiency in the surveillance of other invasive mosquito species, and specifically the major vector Aedes aegypti which is already present in some parts of Europe. Graphical abstract: [Figure not available: see fulltext.] © 2021, The Author(s)
ANALISIS MULTITEMPORAL DEL CAMBIO DE COBERTURA VEGETAL DE LA MICROCUENCA EL VOLCÁN A PARTIR DE LA COMPRA DE ÁREAS ESTRATÉGICAS.
El objetivo de la presente investigación fue determinar los cambios de la cobertura vegetal entre los años 1992 a 2017 de la microcuenca El Volcán, Pamplona, Norte de Santander, para determinar los cambios de las coberturas antes y después de la compra de áreas estratégicas. Para esto, se seleccionaron y procesaron imágenes satelitales de 1992, 1997, 2014 y 2017 correspondientes a los años definidos; luego, se aplicó la metodología Corine Land Cover a escala 1:100000 adaptada para Colombia. El procesamiento de la información se realizó mediante el software ArcGIS con una escala 1:25000. Los resultados revelaron una recuperación positiva de las áreas de protección, mientras que la microcuenca presenta una variación entorno a la cobertura vegetal, con influencia de los sistemas productivos en áreas boscosas, áreas con procesos de recuperación y disminución de otras coberturas
A simple one-pot oxidation protocol for the synthesis of dehydrohedione from Hedione
A new method for the oxidation of Hedione 1 to dehydrohedione 2, a high value intermediate in the flavour and fragrance industry, has developed based upon one pot α-chlorination-elimination sequence which can be readily scaled. The spontaneous elimination of the α-chloro in methanol was unprecedented and has allowed for the oxidation, typically performed in multiple steps/reactions, to be carried out as a one-pot protocol. A continuous flow process for performing the reaction utilising sulfuryl chloride has also demonstrated allowing for steady, safe evolution of SO2 gas during the reaction
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