119 research outputs found
Iridoids as DNA topoisomerase I poisons
The discovery of new topoisomerase I inhibitors is necessary since most of the antitumor drugs are targeted against type II and
only a very few can specifically affect type I. Topoisomerase poisons generate toxic DNA damage by stabilization of the
covalent DNA-topoisomerase cleavage complex and some have therapeutic efficacy in human cancer. Two iridoids, aucubin
and geniposide, have shown antitumoral activities, but their activity against topoisomerase enzymes has not been tested. Here
it was found that both compounds are able to stabilize covalent attachments of the topoisomerase I subunits to DNA at sites of
DNA strand breaks, generating cleavage complexes intermediates so being active as poisons of topoisomerase I, but not
topoisomerase II. This result points to DNA damage induced by topoisomerase I poisoning as one of the possible mechanisms
by which these two iridoids have shown antitumoral activity, increasing interest in their possible use in cancer
chemoprevention and therapy.Ministerio de Ciencia y Tecnología de España. SAF 2000-016
Curcumin as a DNA Topoisomerase II Poison
Curcumin, the major active component of the spice
turmeric, is recognised as a safe compound with great
potential for cancer chemoprevention and cancer therapy.
It induces apoptosis, but its initiation mechanism
remains poorly understood. Curcumin has been assessed
on the human cancer cell lines, TK-10, MCF-7 and UACC62, and their IC50 values were 12.16, 3.63, 4.28 mM
respectively. The possibility of this compound being a
topoisomerase II poison has also been studied and it was
found that 50 mM of curcumin is active in a similar
fashion to the antineoplastic agent etoposide. These
results point to DNA damage induced by topoisomerase
II poisoning as a possible mechanism by which curcumin
initiates apoptosis, and increase the evidence suggesting
its possible use in cancer therapy.Ministerio de Ciencia y Tecnología de España. SAF 2000-016
Flavonoids As DNA Topoisomerase I Poisons
The therapeutic anticancer potential of flavonoids shown
by recent research needs a greater understanding of these
compounds. They are antioxidants and antimutagenic
agents that can inhibit tumor promotion and transformation and can modify the activity of a large number of
mammalian enzyme systems, such as human DNAtopoisomerases. Poisons of topoisomerases generate
toxic DNA damage by stabilization of the covalent
DNA-topoisomerase cleavage complex and some of them
have therapeutic efficacy in human cancer. The present
investigation has assayed ten flavonoids, isolated in our
laboratory, as topoisomerase I poisons obtaining myricetin and myricetin-3-galactoside as two new topoiosomerase I poisons. These two flavonoids, and the plant
extract from which they were isolated, were assayed for
cytotoxic activity against three human cancer cell lines
using the SRB assay. Taking into account our previous
research, structural requisites implicated in the
topoisomerase poisoning are discussed.Ministerio de Ciencia y Tecnología de España. SAF 2000-016
Simulation of a biorefinery process as learning tool in chemical engineering degree
Currently, the search for alternative biomass to be used as renewable sources for energy production is one of the most important challenges to achieve a sustainable growth based on a bioeconomy strategy (Mendes et al., 2009). In this context, lignocellulosic waste are a renewable, clean, inexpensive and with high availability for the manufacture of biofuels. In this sense, the main objective of this study was the simulation and design of engineering processes that allows the valorization of lignocellulosic waste and the obtaining of biofuels as alternative to fossil fuels. This goal implies the practical application of the theoretical knowledge acquired by the student during the chemical engineering degree. Specifically, the students designed and simulated a biorefinery process that consisted of a Kraft pulping process as starting point of two main lines of production: (1) Process I: production of bioethanol and (2) Process II: direct and indirect production of dimethylether (DME), both from lignocellulosic biomass (Fig.1). Two commercial simulation packages, ASPEN HYSYS® and UNISIM were used to simulate the production of dimethylether and bioethanol, respectively.
The first step was determining a strategic situation for the installation of the biorefinery. The central area of Andalusia (between the municipalities of Lucena and Antequera) was considered the most adequate area to develop the installation of the biorefinery plant after evaluating the biomass available inside of 100 kms of distance around this place. Specifically, different biomass mixtures were considered in order to ensure the viability of a constant inlet flow of biomass in the biorefinery. In function of this inlet flow of biomass, the installations were designed and dimensioned in each stage of the process. The student carried out a wide revision of state of the art to decide the most adequate processes among different alternatives to obtain dimethylether and bioethanol. The different stages selected as the most adequate in each line of the process can be observed in Fig.1. Moreover, the students evaluated the different alternatives for the valorisation and optimization of the by-products generated in each stage of the process in order to minimize the consuming of chemical compounds and energy requirements. Therefore, the students learnt to develop a real engineering process more sustainable and friendly with the environment.
To sum up, the used of programs to simulate the transformation of lignocellulosic biomass in biofuels, such as, bioethanol or dimethylether, which is a process with several social, environmental and economic advantages, was an interesting learning tool for students of chemical engineering degree.
Keywords
Bioethanol, design, dimethylether, Kraft pulping process, simulations.
References
Mendes, C.V.T., Carvalho, M.G.V.S., Baptista, C.M.S.G., Rocha, J.M.S., Soares, B.I.G., Sousa, G.D.A., 2009. Valorisation of hardwood hemicelluloses in the kraft pulping process by using an integrated biorefinery concept. Food Bioproduct Process 87:197–207.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
MINECO: Proyecto CTQ2015-68654-
Estudio MEPAFAC I: medida de presión arterial en adolescentes realizada por farmacéuticos comunitarios en centros escolares. Educación sobre factores de riesgo cardiovascular
INTRODUCCIÓN Conocer valores de presión arterial en la población juvenil va a permitir identificar individuos predispuestos a presentar enfermedades cardiovasculares y a diseñar estrategias de prevención.OBJETIVOS Obtener valores de medida de presión arterial con aparatos oscilométricos en una muestra de jóvenes escolares de ambos sexos, entre 12 y 17 años de edad y realizar Educación Sanitaria a los participantes en el estudio.MATERIAL Y MÉTODOS Estudio epidemiológico, observacional, transversal y multicéntrico realizado en Centros Escolares de la Comunidad Autónoma de Madrid, sobre una muestra estimada de 2.500 jóvenes elegidos mediante un muestreo por conglomerados. Se les realizará una encuesta sobre hábitos de vida, un examen antropométrico: peso, talla, índice de masa corporal, medida de la presión arterial y se les proporcionará educación sanitaria mediante una charla formativa.UTILIDAD DEL ESTUDIO Conocer los valores de referencia de presión arterial y los factores de riesgo cardiovascular de nuestros adolescentes no tiene por si mismo ninguna utilidad práctica si no va acompañado de una intervención efectiva para prevenir el desarrollo de ECV. Los cambios en el estilo de vida tienen un nivel de recomendación A. El farmacéutico, como se espera poner de manifiesto en el estudio, puede ejercer de educador sanitario para promover estilos de vida saludable.INTRODUCCIÓN Conocer valores de presión arterial en la población juvenil va a permitir identificar individuos predispuestos a presentar enfermedades cardiovasculares y a diseñar estrategias de prevención. OBJETIVOS Obtener valores de medida de presión arterial con aparatos oscilométricos en una muestra de jóvenes escolares de ambos sexos, entre 12 y 17 años de edad y realizar Educación Sanitaria a los participantes en el estudio. MATERIAL Y MÉTODOS Estudio epidemiológico, observacional, transversal y multicéntrico realizado en Centros Escolares de la Comunidad Autónoma de Madrid, sobre una muestra estimada de 2.500 jóvenes elegidos mediante un muestreo por conglomerados. Se les realizará una encuesta sobre hábitos de vida, un examen antropométrico: peso, talla, índice de masa corporal, medida de la presión arterial y se les proporcionará educación sanitaria mediante una charla formativa. UTILIDAD DEL ESTUDIO Conocer los valores de referencia de presión arterial y los factores de riesgo cardiovascular de nuestros adolescentes no tiene por si mismo ninguna utilidad práctica si no va acompañado de una intervención efectiva para prevenir el desarrollo de ECV. Los cambios en el estilo de vida tienen un nivel de recomendación A. El farmacéutico, como se espera poner de manifiesto en el estudio, puede ejercer de educador sanitario para promover estilos de vida saludable
Induction of Apoptosis and Cell Cycle Arrest in Human Colon Carcinoma Cells by Corema album Leaves
The leaves of Corema album (Ericaceae), an endemic shrub which grows in Atlantic coastal areas of the Iberian Peninsula, are rich in flavonoids and other
secondary metabolites. Silica gel column chromatography of the ethyl acetate extract from dried leaves was performed and a flavonic active fraction was
obtained. The cytotoxic activity of this fraction was assessed using the colon cancer cell lines HCT116 and HT29. After 48 hours of treatment, cell viability
was determined with luminescence-based ATPLite assay, showing IC50 values of 7.2 ± 0.7 and 6.8 ± 1.2 µg/mL, respectively. The study by flow cytometry
revealed that the cytotoxicity of this fraction was mediated, at least in part, by induction of apoptosis and G2/M cell cycle arrest. The active fraction was then
subjected to Sephadex LH-20 chromatography and two flavonoids were separated and identified as the flavanone pinocembrin and 2’,4’-dihydroxychalcone
after UV, MS and NMR analysis
Cytotoxic activity of methanolic extract and two alkaloids extracted from seeds of Peganum harmala L.
To study the cytotoxic activity of P. harmala. Materials and method: The alkaloids harmine and harmaline have been isolated from a methanolic extract from the seeds of P. harmala L. and have been characterized by spectroscopic-Mass and NMR methods. The cytotoxicity of the methanolic extract and both alkaloids has been investigated in the three human cancer cell lines UACC-62 (melanoma), TK-10 (renal) and MCF-7 (breast) and then compared to the positive control effect of the etoposide. Results and conclusion: The methanolic extract and both alkaloids have inhibited the growth of these three cancer cell-lines and we have discussed possible mechanisms involved in their cytotoxicity
Phytochemical Profile and Antibacterial Activity of Retama raetam and R. sphaerocarpa cladodes from Algeria
Retama raetam (RR) and R. sphaerocarpa (RS) are shrubs growing in Algeria desert areas, where are commonly used as healing remedies because of their
antiseptic, antipyretic and anti-diarrheal properties. Phytochemical studies have shown that these species are very rich in flavonoids (isoflavones) and alkaloids
(quinolizidine and bipiperidyl). The aim of this study was to compare the chemical composition of both Retama species by GC/MS and LC/MS and to
determinate their antimicrobial activity of two Retama species growing naturally in Algeria. Ten alkaloids and seven flavonoids were identified in cladodes of
RR and RS. The quantitative analysis showed that the most abundant flavonoid of both the aqueous extract from RR and RS was the isoflavone genistein
(610.0±2.8 and 408.0±14.1 mg/100 g respectively), whereas sparteine was the predominant alkaloid in RR and retamine in RS. The antibacterial activity of
Retama extracts against standard strains was performed by minimum inhibitory concentration (MIC), and by the disc diffusion method (expressed by inhibition
zone, IZ). Both Retama species showed the best activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), being RS aqueous extract
more active than RR aqueous extract, with MIC 125 µg/mL and bactericidal activity against both strains
Cirugía de implantación de microestimulador del ganglio esfenopalatino. Manejo anestésico y revisión de la literatura
Cluster headache is a trigeminal-autonomic headache with severe symptoms due to recurrent intense pain and ipsilateral autonomic manifestations. Medical treatment is not always succesful or may be poorly tolerated for side effects. The development of surgical technics who involve the stimulation of the pain centers, is a new and hopeful tool for these patients. Althought a correct surgery, anesthesia may be careful and must fit into a board surgical orofacial field. We expose a case for chronic and refractory cluster headache, treated by sphenopalatine ganglion microstimulator surgical insertion under general anesthesia. La cefalea en racimos es un tipo de cefalea trigémino-autonómica con síntomas marcadamente disfuncionales debidos al intenso dolor y a la aparición de signos disautonómicos hemicraneales ipsilaterales recurrentes. El tratamiento médico no siempre resulta eficaz o puede no tolerarse debido a sus efectos adversos. El desarrollo de técnicas quirúrgicas que inciden en el tratamiento a través de la estimulación de estructuras directamente relacionadas con el dolor, supone una nueva y esperanzadora herramienta terapéutica para este tipo de pacientes. Además de una cirugía correcta, el tipo de anestesia para la intervención debe ser cuidadosa y adecuarse a la necesidad de trabajar sobre un campo quirúrgico oro-facial amplio. Presentamos dos casos de pacientes con cefalea en racimos de evolución crónica y refractaria a tratamiento, sometidos a la implantación quirúrgica de un microestimulador en el ganglio esfenopalatino bajo anestesia general
Actividad citotóxica de la fracción de acetato de etilo de un extracto obtenido de Viscum cruciatum Sieber
Actividad citotóxica de la fracción de acetato de etilo de
un extracto obtenido de Viscum cruciatum Sieber.
La presente invención tiene por objeto a un extracto de
Viscum cruciatum Sieber, con actividad citotóxica, así como a los principios activos aislados que son venenos de
topoisomerasa II, las composiciones farmacológicas que
contienen tanto al extracto como a los principios activos
aislados de ésta y al uso de estas composiciones en la
preparación de un medicamento para el tratamiento del
cáncer. La presente invención tiene su aplicación en el
campo de la medicina.Españ
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