998 resultados para anti-hero
Resumo:
Background: Documenting the distribution of radiotherapy departments and the availability of radiotherapy equipment in the European countries is an important part of HERO the ESTRO Health Economics in Radiation Oncology project. HERO has the overall aim to develop a knowledge base of the provision of radiotherapy in Europe and build a model for health economic evaluation of radiation treatments at the European level. The aim of the current report is to describe the distribution of radiotherapy equipment in European countries. Methods: An 84-item questionnaire was sent out to European countries, principally through their national societies. The current report includes a detailed analysis of radiotherapy departments and equipment (questionnaire items 2629), analyzed in relation to the annual number of treatment courses and the socio-economic status of the countries. The analysis is based on validated responses from 28 of the 40 European countries defined by the European Cancer Observatory (ECO). Results: A large variation between countries was found for most parameters studied. There were 2192 linear accelerators, 96 dedicated stereotactic machines, and 77 cobalt machines reported in the 27 countries where this information was available. A total of 12 countries had at least one cobalt machine in use. There was a median of 0.5 simulator per MV unit (range 0.31.5) and 1.4 (range 0.44.4) simulators per department. Of the 874 simulators, a total of 654 (75%) were capable of 3D imaging (CT-scanner or CBCToption). The number of MV machines (cobalt, linear accelerators, and dedicated stereotactic machines) per million inhabitants ranged from 1.4 to 9.5 (median 5.3) and the average number of MV machines per department from 0.9 to 8.2 (median 2.6). The average number of treatment courses per year per MV machine varied from 262 to 1061 (median 419). While 69% of MV units were capable of IMRT only 49% were equipped for image guidance (IGRT). There was a clear relation between socio-economic status, as measured by GNI per capita, and availability of radiotherapy equipment in the countries. In many low income countries in Southern and Central-Eastern Europe there was very limited access to radiotherapy and especially to equipment for IMRT or IGRT. Conclusions: The European average number of MV machines per million inhabitants and per department is now better in line with QUARTS recommendations from 2005, but the survey also showed a significant heterogeneity in the access to modern radiotherapy equipment in Europe. High income countries especially in Northern-Western Europe are well-served with radiotherapy resources, other countries are facing important shortages of both equipment in general and especially machines capable of delivering high precision conformal treatments (IMRT, IGRT)
Resumo:
Background: The ESTRO Health Economics in Radiation Oncology (HERO) project has the overall aim to develop a knowledge base of the provision of radiotherapy in Europe and build a model for health economic evaluation of radiation treatments at the European level. The first milestone was to assess the availability of radiotherapy resources within Europe. This paper presents the personnel data collected in the ESTRO HERO database. Materials and methods: An 84-item questionnaire was sent out to European countries, through their national scientific and professional radiotherapy societies. The current report includes a detailed analysis of radiotherapy staffing (questionnaire items 4760), analysed in relation to the annual number of treatment courses and the socio-economic status of the countries. The analysis was conducted between February and July 2014, and is based on validated responses from 24 of the 40 European countries defined by the European Cancer Observatory (ECO). Results: A large variation between countries was found for most parameters studied. Averages and ranges for personnel numbers per million inhabitants are 12.8 (2.530.9) for radiation oncologists, 7.6 (019.7) for medical physicists, 3.5 (012.6) for dosimetrists, 26.6 (1.978) for RTTs and 14.8 (0.461.0) for radiotherapy nurses. The combined average for physicists and dosimetrists is 9.8 per million inhabitants and 36.9 for RTT and nurses. Radiation oncologists on average treat 208.9 courses per year (range: 99.9348.8), physicists and dosimetrists conjointly treat 303.3 courses (range: 85757.7) and RTT and nurses 76.8 (range: 25.7156.8). In countries with higher GNI per capita, all personnel categories treat fewer courses per annum than in less affluent countries. This relationship is most evident for RTTs and nurses. Different clusters of countries can be distinguished on the basis of available personnel resources and socio-economic status. Conclusions: The average personnel figures in Europe are now consistent with, or even more favourable than the QUARTS recommendations, probably reflecting a combination of better availability as such, in parallel with the current use of more complex treatments than a decade ago. A considerable variation in available personnel and delivered courses per year however persists among the highest and lowest staffing levels. This not only reflects the variation in cancer incidence and socio-economic determinants, but also the stage in technology adoption along with treatment complexity and the different professional roles and responsibilities within each country. Our data underpin the need for accurate prediction models and long-term education and training programmes
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The replicative cycle of HIV presents several events. The proteins involved in these events can be anticipated as pharmacological targets, aiming to the development of anti viral agents. Presently, there are fifteen commercially available anti-HIV drugs, which act at substrate binding site of reverse transcriptase (zidovudine, didanosine, zalcitabine, stavudine, lamivudine and abacavir), at a non-substrate binding site of reverse transcriptase (nevirapine, delavirdine and efavirenz), or by inhibiting HIV protease activity (saquinavir, ritonavir, indinavir, nelfinavir, amprenavir and lopinavir). The present review focus both on these established classes of drugs and on new classes of compounds acting on other virus specific steps.
Resumo:
Currently available anti-HIV drugs can be classified into three categories: nucleoside analogue reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs). In addition to the reverse transcriptase (RT) and protease reaction, various other events in the HIV replicative cycle can be considered as potential targets for chemotherapeutic intervention: (1) viral adsorption, through binding to the viral envelope glycoprotein gp120; (2) viral entry, through blockage of the viral coreceptors CXCR4 and CCR5; (3) virus-cell fusion, through binding to the viral envelope glycoprotein gp 41; (4) viral assembly and disassembly through NCp7 zinc finger-targeted agents; (5) proviral DNA integration, through integrase inhibitors and (6) viral mRNA transcription, through inhibitors of the transcription (transactivation) process. Also, various new NRTIs, NNRTIs and PIs have been developed, possessing different improved characteristics.
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Coherent anti-Stokes Raman scattering (CARS) microscopy is rapidly developing into a unique microscopic tool in biophysics, biology and the material sciences. The nonlinear nature of CARS spectroscopy complicates the analysis of the received spectra. There were developed mathematical methods for signal processing and for calculations spectra. Fourier self-deconvolution is a special high pass FFT filter which synthetically narrows the effective trace bandwidth features. As Fourier self-deconvolution can effectively reduce the noise, which may be at a higher spatial frequency than the peaks, without losing peak resolution. The idea of the work is to experiment the possibility of using wavelet decomposition in spectroscopic for background and noise removal, and Fourier transformation for linenarrowing.
Resumo:
Optimization of an essentially inactive 3,4-dihydro-2H-pyrano[3,2-c]quinoline carboxylic ester derivative as acetylcholinesterase (AChE) peripheral anionic site (PAS)-binding motif by double O → NH bioisosteric replacement, combined with molecular hybridization with the AChE catalytic anionic site (CAS) inhibitor 6-chlorotacrine and molecular dynamics-driven optimization of the length of the linker has resulted in the development of the trimethylene-linked 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridine6-chlorotacrine hybrid 5a as a picomolar inhibitor of human AChE (hAChE). The tetra-, penta-, and octamethylene-linked homologues 5bd have been also synthesized for comparison purposes, and found to retain the nanomolar hAChE inhibitory potency of the parent 6-chlorotacrine. Further biological profiling of hybrids 5ad has shown that they are also potent inhibitors of human butyrylcholinesterase and moderately potent Aβ42 and tau anti-aggregating agents, with IC50 values in the submicromolar and low micromolar range, respectively. Also, in vitro studies using an artificial membrane model have predicted a good brain permeability for hybrids 5ad, and hence, their ability to reach their targets in the central nervous system. The multitarget profile of the novel hybrids makes them promising leads for developing anti-Alzheimer drug candidates with more balanced biological activities.
Resumo:
Optimization of an essentially inactive 3,4-dihydro-2H-pyrano[3,2-c]quinoline carboxylic ester derivative as acetylcholinesterase (AChE) peripheral anionic site (PAS)-binding motif by double O → NH bioisosteric replacement, combined with molecular hybridization with the AChE catalytic anionic site (CAS) inhibitor 6-chlorotacrine and molecular dynamics-driven optimization of the length of the linker has resulted in the development of the trimethylene-linked 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridine6-chlorotacrine hybrid 5a as a picomolar inhibitor of human AChE (hAChE). The tetra-, penta-, and octamethylene-linked homologues 5bd have been also synthesized for comparison purposes, and found to retain the nanomolar hAChE inhibitory potency of the parent 6-chlorotacrine. Further biological profiling of hybrids 5ad has shown that they are also potent inhibitors of human butyrylcholinesterase and moderately potent Aβ42 and tau anti-aggregating agents, with IC50 values in the submicromolar and low micromolar range, respectively. Also, in vitro studies using an artificial membrane model have predicted a good brain permeability for hybrids 5ad, and hence, their ability to reach their targets in the central nervous system. The multitarget profile of the novel hybrids makes them promising leads for developing anti-Alzheimer drug candidates with more balanced biological activities.
Resumo:
Optimization of an essentially inactive 3,4-dihydro-2H-pyrano[3,2-c]quinoline carboxylic ester derivative as acetylcholinesterase (AChE) peripheral anionic site (PAS)-binding motif by double O → NH bioisosteric replacement, combined with molecular hybridization with the AChE catalytic anionic site (CAS) inhibitor 6-chlorotacrine and molecular dynamics-driven optimization of the length of the linker has resulted in the development of the trimethylene-linked 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridine6-chlorotacrine hybrid 5a as a picomolar inhibitor of human AChE (hAChE). The tetra-, penta-, and octamethylene-linked homologues 5bd have been also synthesized for comparison purposes, and found to retain the nanomolar hAChE inhibitory potency of the parent 6-chlorotacrine. Further biological profiling of hybrids 5ad has shown that they are also potent inhibitors of human butyrylcholinesterase and moderately potent Aβ42 and tau anti-aggregating agents, with IC50 values in the submicromolar and low micromolar range, respectively. Also, in vitro studies using an artificial membrane model have predicted a good brain permeability for hybrids 5ad, and hence, their ability to reach their targets in the central nervous system. The multitarget profile of the novel hybrids makes them promising leads for developing anti-Alzheimer drug candidates with more balanced biological activities.
Resumo:
Optimization of an essentially inactive 3,4-dihydro-2H-pyrano[3,2-c]quinoline carboxylic ester derivative as acetylcholinesterase (AChE) peripheral anionic site (PAS)-binding motif by double O → NH bioisosteric replacement, combined with molecular hybridization with the AChE catalytic anionic site (CAS) inhibitor 6-chlorotacrine and molecular dynamics-driven optimization of the length of the linker has resulted in the development of the trimethylene-linked 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridine6-chlorotacrine hybrid 5a as a picomolar inhibitor of human AChE (hAChE). The tetra-, penta-, and octamethylene-linked homologues 5bd have been also synthesized for comparison purposes, and found to retain the nanomolar hAChE inhibitory potency of the parent 6-chlorotacrine. Further biological profiling of hybrids 5ad has shown that they are also potent inhibitors of human butyrylcholinesterase and moderately potent Aβ42 and tau anti-aggregating agents, with IC50 values in the submicromolar and low micromolar range, respectively. Also, in vitro studies using an artificial membrane model have predicted a good brain permeability for hybrids 5ad, and hence, their ability to reach their targets in the central nervous system. The multitarget profile of the novel hybrids makes them promising leads for developing anti-Alzheimer drug candidates with more balanced biological activities.
Resumo:
Multitarget compounds are increasingly being pursued for the effective treatment of complex diseases. Herein, we describe the design and synthesis of a novel class of shogaolhuprine hybrids, purported to hit several key targets involved in Alzheimer"s disease. The hybrids have been tested in vitro for their inhibitory activity against human acetylcholinesterase and butyrylcholinesterase and antioxidant activity (ABTS.+, DPPH and Folin-Ciocalteu assays), and in intact Escherichia coli cells for their Aβ42 and tau anti-aggregating activity. Also, their brain penetration has been assessed (PAMPA-BBB assay). Even though the hybrids are not as potent AChE inhibitors or antioxidant agents as the parent huprine Y and [4]-shogaol, respectively, they still exhibit very potent anticholinesterase and antioxidant activities and are much more potent Aβ42 and tau anti-aggregating agents than the parent compounds. Overall, the shogaolhuprine hybrids emerge as interesting brain permeable multitarget anti-Alzheimer leads.
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The concept of research and the controversy among classical models for C, T & I, outdated by the development of knowledge and Post-modern society needs were revisited through the (3) Quadrants advanced by Donald Stokes in the mid-nineties. The scientific community to fit into these Quadrants was faced with many difficulties and reacted by issuing pseudo-facts, accepted by under-prepared technocrats as viable justifications for conducting research in face of these new paradigms. In a poor country full of contrast and needs such as Brazil, this attitude satisfies the bureaucracy and academic elite, but frustrates government and society, that do not get, in the expected measure, the benefits of their commitment with the Teaching, Research and Extension Sectors mainly embedded in the Public University system. An extension, in fact a contradictory approach, to Pasteur's Quadrant, is proposed to characterize this situation: The Syndrome of Ruetsap's Quadrant.
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Aging is associated with common conditions, including cancer, diabetes, cardiovascular disease, and Alzheimer"s disease. The type of multi‐targeted pharmacological approach necessary to address a complex multifaceted disease such as aging might take advantage of pleiotropic natural polyphenols affecting a wide variety of biological processes. We have recently postulated that the secoiridoids oleuropein aglycone (OA) and decarboxymethyl oleuropein aglycone (DOA), two complex polyphenols present in health‐promoting extra virgin olive oil (EVOO), might constitute a new family of plant‐produced gerosuppressant agents. This paper describes an analysis of the biological activity spectra (BAS) of OA and DOA using PASS (Prediction of Activity Spectra for Substances) software. PASS can predict thousands of biological activities, as the BAS of a compound is an intrinsic property that is largely dependent on the compound"s structure and reflects pharmacological effects, physiological and biochemical mechanisms of action, and specific toxicities. Using Pharmaexpert, a tool that analyzes the PASS‐predicted BAS of substances based on thousands of"mechanism‐ effect" and"effect‐mechanism" relationships, we illuminate hypothesis‐generating pharmacological effects, mechanisms of action, and targets that might underlie the anti‐aging/anti‐cancer activities of the gerosuppressant EVOO oleuropeins.
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Prodigiosin and obatoclax, members of the prodiginines family, are small molecules with anti-cancer properties that are currently under preclinical and clinical trials. The molecular target(s) of these agents, however, is an open question. Combining experimental and computational techniques we find that prodigiosin binds to the BH3 domain in some BCL-2 protein families, which play an important role in the apoptotic programmed cell death. In particular, our results indicate a large affinity of prodigiosin for MCL-1, an anti-apoptotic member of the BCL-2 family. In melanoma cells, we demonstrate that prodigiosin activates the mitochondrial apoptotic pathway by disrupting MCL-1/BAK complexes. Computer simulations with the PELE software allow the description of the induced fit process, obtaining a detailed atomic view of the molecular interactions. These results provide new data to understand the mechanism of action of these molecules, and assist in the development of more specific inhibitors of anti-apoptotic BCL-2 proteins.
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Phenolic contents of extracts of Syzygium cumini leaves, collected monthly over a one-year period, were quantitatively determined by the modified Folin-Ciocalteau method. Extracts and tannin-free fractions were assayed by their potential to inhibit mouse paw edema induced by C48/80. HPLC showed high molecular weight phenolic species and flavonoids in the active extracts and fractions. The highest total phenolic content corresponded to the most potent degree of inhibition and the flavonoids were supposed to be the main species responsible for the activity, given that the flavonoid-enriched ethyl-acetate fraction maintained its effect down to a dose of 0.01 mg/kg in a dose-response manner.
Resumo:
We have synthesized a family of rhein-huprine hybrids to hit several key targets for Alzheimer"s disease. Biological screening performed in vitro and in Escherichia coli cells has shown that these hybrids exhibit potent inhibitory activities against human acetylcholinesterase butyrylcholinesterase, and BACE-1, dual Aβ42 and tau anti-aggregating activity, and brain permeability. Ex vivo studies with the leads (+)- and (-)-7e in brain slices of C57bl6 mice have revealed that they efficiently protect against the Aβ-induced synaptic dysfunction , preventing the loss of synaptic proteins and/or have a positive effect on the induction of long term potentiation. In vivo studies in APP-PS1 transgenic mice treated i.p. for 4 weeks with (+)- and (-)-7e have shown a central soluble Aβ lowering effect, accompanied by an increase in the levels of mature amyloid precursor protein (APP). Thus, (+)- and (-)-7e emerge as very promising disease-modifying anti-Alzheimer drug candidates.