1,763 research outputs found
Herbal medicines in Brazil: pharmacokinetic profile and potential herb-drug interactions
A plethora of active compounds found in herbal medicines can serve as substrate for enzymes involved in the metabolism of xenobiotics. When a medicinal plant is co-administered with a conventional drug and little or no information is known about the pharmacokinetics of the plant metabolites, there is an increased risk of potential herb-drug interactions. Moreover, genetic polymorphisms in a population may act to predispose individuals to adverse reactions. The use of herbal medicines is rapidly increasing in many countries, particularly Brazil where the vast biodiversity is a potential source of new and more affordable treatments for numerous conditions. Accordingly, the Brazilian Unified Public Health System (SUS) produced a list of 71 plant species of interest, which could be made available to the population in the near future. Physicians at SUS prescribe a number of essential drugs and should herbal medicines be added to this system the chance of herb-drug interactions further increases. A review of the effects of these medicinal plants on Phase 1 and Phase 2 metabolic mechanisms and the transporter P-glycoprotein was conducted. The results have shown that approximately half of these medicinal plants lack any pharmacokinetic data. Moreover, most of the studies carried out are in vitro. Only a few reports on herb-drug interactions with essential drugs prescribed by SUS were found, suggesting that very little attention is being given to the safety of herbal medicines. Here we have taken this information to discuss the potential interactions between herbal medicines and essential drugs prescribed to Brazilian patients whilst taking into account the most common polymorphisms present in the Brazilian population. A number of theoretical interactions are pinpointed but more pharmacokinetic studies and pharmacovigilance data are needed to ascertain their clinical significance
Friends or Foes? Cytotoxicity, HPTLC and NMR Analyses of Some Important Naturally Occurring Hydroxyanthraquinones
Hydroxyanthraquinones from plants have been used as both medicinal active ingredients and adulterants in slimming food supplements. Although sensible doses of certain natural hydroxyanthraquinones for laxative effects are generally safe in the short term, chronic intake has been related to tumorigenic, carcinogenic, and genotoxic effects. However, an increasing number of researchers are reporting the antiproliferative properties of the same ingredients in cancer cells, pointing towards a potential nutraceutical value for cancer prevention. Previous studies have evaluated anthraquinonesâ anti-proliferative activity against various tumour cell lines and bioavailability in Caco-2 cells. However, there are scarce data about both their cytotoxicity in the later cell line and long-term stability. Therefore, this study will check the purity of several âagedâ samples using mutually complementary analytical techniques such as HPTLC and NMR assays as well as evaluate the anti-proliferative activity of the purest of these samples using the Caco-2 cell line. The chromatographic and spectroscopic analyses confirmed the long-term stability of those compounds, and their cytotoxic activity resulted in chrysazin (15 ”g/mL) > catenarin (27.29 ”g/mL) > rhein (49.55 ”g/mL) > helminthosporin (52.91 ”g/mL) > aloe-emodin (55.34 ”g/mL). Our succinct review of the cytotoxicity of these compounds afforded two results: that this is the first clear report for catenarin being active in colon cancer cells and that this class of compounds needs to be better studied to clearly evaluate their benefit/risk profile in regard to both new chemo preventative nutraceuticals and anticancer therapies
Spectroscopic characterization of mitochondrial G-quadruplexes
Guanine quadruplexes (G4s) are highly polymorphic four-stranded structures formed within guanine-rich DNA and RNA sequences that play a crucial role in biological processes. The recent discovery of the first G4 structures within mitochondrial DNA has led to a small revolution in the field. In particular, the G-rich conserved sequence block II (CSB II) can form different types of G4s that are thought to play a crucial role in replication. In this study, we decipher the most relevant G4 structures that can be formed within CSB II: RNA G4 at the RNA transcript, DNA G4 within the non-transcribed strand and DNA:RNA hybrid between the RNA transcript and the non-transcribed strand. We show that the more abundant, but unexplored, G6AG7 (37%) and G6AG8 (35%) sequences in CSB II yield more stable G4s than the less profuse G5AG7 sequence. Moreover, the existence of a guanine located 1 bp upstream promotes G4 formation. In all cases, parallel G4s are formed, but their topology changes from a less ordered to a highly ordered G4 when adding small amounts of potassium or sodium cations. Circular dichroism was used due to discriminate different conformations and topologies of nucleic acids and was complemented with gel electrophoresis and fluorescence spectroscopy studiesThis research was funded by the Gobierno de EspañaâMinisterio de EconomĂa y Competitividad, grant number CTQ2014-59020-R, the Xunta de Galicia, grant numbers ED431B 2019/18, ED431G 2019/03 Centro singular de investigaciĂłn de Galicia accreditation 2019â2022, and Ph.D. fellowship to S.I. and the European Union (European Regional Development FundâERDF)S
Preservice sciencie teacher education : Inquiry into professional practical problems
We present a proposal for preservice science teacher education entitled
âAprendiendo a Enseñar Ciencias en Primaria -Learning to Teach Primary Science-
(APENCIP Workbook)" (Rivero et al., 2012). We take as referents for this workbook:
inquiry-based science education; teacher education by inquiry into professional
practical problems; the interaction with innovative teaching practices through
audiovisuals. In the first part, the students prepare a plan to teach some specific
content. The discussion and analysis of their proposals will serve as an initial contrast
between the different teams, and an introduction to the professional problems they
will have to address during the course (the intention being to clearly relate these
problems with elements of the curriculum). In the second part, each curricular element
and the problems it raises will be worked on sequentially. We shall begin by
analysing the first version, and then compare and contrast it with various documents.
The process culminates with work on a script for reflection aimed at setting out each
team's position relative to the curricular element being analysed, and the team
members' responses to the problems addressed. After analysing all the curricular
elements selected, a second version of the teaching plan will be elaborated. In the
third part, how inquiry-based science education is actually put into practice in the
classroom will be visualized from video material and analysed, and a third version of
the plan will be elaborated. The final activity is to compare the three versions, and to
evaluate the entire process. Our intention is to investigate the prospective teachers'
progression of knowledge in this process, and the possible influence that the course,
especially the use of videos, may have had on that progression. Cur
Patient and Public Involvement in Sexual and Reproductive Health: Time to Properly Integrate Citizenâs Input into Science
Evidence-based sexual and reproductive health is a global endeavor without borders.
Inter-sectorial collaboration is essential for identifying and addressing gaps in evidence.
Health research funders and regulators are promoting patient and public involvement in research,
but there is a lack of quality tools for involving patients. Partnerships with patients are necessary
to produce and promote robust, relevant and timely research. Without the active participation of
women as stakeholders, not just as research subjects, the societal benefits of research cannot be
realized. Creating and developing platforms and opportunities for public involvement in sexual and
reproductive health research should be a key international objective. Cooperation between healthcare
professionals, academic institutions and the community is essential to promote quality research and
significant developments in womenâs health. This cooperation will be improved when involvement
of citizens in the research process becomes standard.Spanish Governmen
Towards Ratiometric Sensing of Amyloid Fibrils In Vitro
This is the peer-reviewed version of the following article: Chemistry - A European Journal 2015, 21, 3425â3434, DOI: 10.1002/chem.201406110.
The final form has been published at https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201406110.
This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe aggregation of amyloidâÎČ peptide and its accumulation in the human brain has an important role in the etiology of Alzheimerâs disease. Thioflavinâ
T has been widely used as a fluorescent marker for these amyloid aggregates. Nevertheless, its complex photophysical behavior, with strong wavelength dependencies of all its fluorescence properties, requires searching for new fluorescent probes. The use of 2â(2âČâhydroxyphenyl)imidazo[4,5âb]pyridine (HPIP), which shows two emission bands and a rich excitedâstate behavior due to the existence of excitedâstate intramolecular processes of proton transfer and charge transfer, is proposed. These properties result in a high sensitivity of HPIP fluorescence to its microenvironment and cause a large differential fluorescence enhancement of the two bands upon binding to aggregates of the amyloidâÎČ peptide. Based on this behavior, a very sensitive ratiometric method is established for the detection and quantification of amyloid fibrils, which can be combined with the monitoring of fluorescence anisotropy. The binding selectivity of HPIP is discussed on the basis of the apparent binding equilibrium constants of this probe to amyloidâÎČ (1â42) fibrils and to the nonfibrillar protein bovine serum albumin. Finally, an exhaustive comparison between HPIP and thioflavinâ
T is presented to discuss the sensitivity and specificity of these probes to amyloid aggregates and the significant advantages of the HPIP dye for quantitative determinationsXunta de Galicia
European Regional Development Fund
Ministerio de Ciencia e InnovaciĂłn
Xunta de Galicia. Grant Numbers: CTQ2010â21369, CTQ2010â17835, GPC2013/052, R2014/051
RS MacDonald Charitable TrustS
The influence of bisphosphonates on human osteoblast migration and integrin aVb3/tenascin C gene expression in vitro
<p>Abstract</p> <p>Background</p> <p>Bisphosphonates are therapeutics of bone diseases, such as Paget's disease, multiple myeloma or osteoclastic metastases. As a severe side effect the bisphosphonate induced osteonecrosis of the jaw (BONJ) often requires surgical treatment and is accompanied with a disturbed wound healing.</p> <p>Therefore, the influence on adhesion and migration of human osteoblasts (hOB) after bisphosphonate therapy has been investigated by morphologic as well as gene expression methods.</p> <p>Methods</p> <p>By a scratch wound experiment, which measures the reduction of defined cell layer gap, the morphology and migration ability of hOB was evaluated. A test group of hOB, which was stimulated by zoledronate 5 Ă 10<sup>-5</sup>M, and a control group of unstimulated hOB were applied. Furthermore the gene expression of integrin aVb3 and tenascin C was quantified by Real-Time rtPCR at 5data points over an experimental period of 14 days. The bisphosphonates zoledronate, ibandronate and clodronate have been compared with an unstimulated hOB control.</p> <p>Results</p> <p>After initially identical migration and adhesion characteristics, zoledronate inhibited hOB migration after 50 h of stimulation. The integrinavb3 and tenascin C gene expression was effected by bisphosphonates in a cell line dependent manner with decreased, respectively inconsistent gene expression levels over time. The non-nitrogen containing bisphosphonates clodronate led to decreased gene expression levels.</p> <p>Conclusion</p> <p>Bisphosphonates seem to inhibit hOB adhesion and migration. The integrin aVb3 and tenascin C gene expression seem to be dependent on the cell line. BONJ could be enhanced by an inhibition of osteoblast adhesion and migration. The gene expression results, however, suggest a cell line dependent effect of bisphosphonates, which could explain the interindividual differences of BONJ incidences.</p
Histiocytoid Sweet Syndrome associated with anorectal lymphogranuloma venereum in a patient with HIV infection
Sweet Syndrome belongs to a group of diseases known as neutrophilic dermatoses. An uncommon variant named Histiocytoid Sweet Syndrome (HSS) can be associated with a variety of conditions, including cancer, infections, drug toxicity and others. Here we present an instance of HSS in an HIV-positive patient in an infectious disease settin
Chemical abundances of late-type pre-main sequence stars in the -Orionis cluster
The young -Orionis cluster is an important location for understanding
the formation and evolution of stars, brown dwarfs, and planetary-mass objects.
Its metallicity, although being a fundamental parameter, has not been well
determined yet. We present the first determination of the metallicity of nine
young late-type stars in -Orionis. Using the optical and near-infrared
broadband photometry available in the literature we derive the effective
temperatures for these nine cluster stars, which lie in the interval 4300--6500
K (1--3 \Msuno). These parameters are employed to compute a grid of synthetic
spectra based on the code MOOG and Kurucz model atmospheres. We employ a
-minimization procedure to derive the stellar surface gravity and
atmospheric abundances of Al, Ca, Si, Fe, Ni and Li, using multi-object optical
spectroscopy taken with WYFFOS+AF2 at at the William Herschel Telescope
(). The average metallicity of the
-Orionis cluster is [Fe/H] (random and
systematic errors). The abundances of the other elements, except lithium, seem
to be consistent with solar values. Lithium abundances are in agreement with
the "cosmic" Li abundance, except for two stars which show a in the range 3.6--3.7 (although almost consistent within
the error bars). There are also other two stars with . We derived an average radial velocity of the
-Orionis cluster of km/s. The -Orionis metallicity is
roughly solar.Comment: Accepted for publication in Astronomy and Astrophysic
- âŠ