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OBJECTIVES: Clinical trials provide one of the highest levels of evidence to support medical practice. Investigator initiated clinical trials (IICTs) answer relevant questions in clinical practice that may not be addressed by industry. For the first time, two European Countries are compared in terms of IICTs, respective funders and publications, envisaging to inspire others to use similar indicators to assess clinical research outcomes. METHODS: A retrospective systematic search of registered IICTs from 2004 to 2017, using four clinical trials registries was carried out in two European countries with similar population, GDP, HDI and medical schools but with different governmental models to fund clinical research. Each IICT was screened for sponsors, funders, type of intervention and associated publications, once completed. RESULTS: IICTs involving the Czech Republic and Portugal were n = 439 (42% with hospitals as sponsors) and n = 328 (47% with universities as sponsors), respectively. The Czech Republic and Portuguese funding agencies supported respectively 61 and 27 IICTs. Among these, trials with medicinal products represent 52% in Czech Republic and 4% in Portugal. In the first, a higher percentage of IICTs' publications in high impact factor journals with national investigators as authors was observed, when compared to Portugal (75% vs 15%). CONCLUSION: The better performance in clinical research by Czech Republic might be related to the existence of specific and periodic funding for clinical research, although further data are still needed to confirm this relationship. In upcoming years, the indicators used herein might be useful to tracking clinical research outcomes in these and other European countries.
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Políticas , República Checa , Humanos , Portugal , Sistema de Registros , Estudios RetrospectivosRESUMEN
Herein, we report a new approach to bio-inspired catalyst design. The molecular catalyst employed in these studies is based on the robust and selective Re(bpy)(CO)3Cl-type (bpy = 2,2'-bipyridine) homogeneous catalysts, which have been extensively studied for their ability to reduce CO2 electrochemically or photochemically in the presence of a photosensitizer. These catalysts can be highly active photocatalysts in their own right. In this work, the bipyridine ligand was modified with amino acids and synthetic peptides. These results build on earlier findings wherein the bipyridine ligand was functionalized with amide groups to promote dimer formation and CO2 reduction by an alternate bimolecular mechanism at lower overpotential (ca. 250 mV) than the more commonly observed unimolecular process. The bio-inspired catalysts were designed to allow for the incorporation of proton relays to support reduction of CO2 to CO and H2O. The coupling of amino acids tyrosine and phenylalanine led to the formation of two structurally similar Re catalyst/peptide catalysts for comparison of proton transport during catalysis. This article reports the synthesis and characterization of novel catalyst/peptide hybrids by molecular dynamics (MD simulations of structural dynamics), NMR studies of solution phase structures, and electrochemical studies to measure the activities of new bio-inspired catalysts in the reduction of CO2.
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Aminoácidos/síntesis química , Dióxido de Carbono/química , Compuestos Organometálicos/química , Péptidos/síntesis química , Protones , Aminoácidos/química , Dióxido de Carbono/metabolismo , Catálisis , Enlace de Hidrógeno , Estructura Molecular , Oxidación-Reducción , Péptidos/químicaRESUMEN
A series of [Cp*Ir(III)(R-bpy)Cl]Cl (R-bpy = 4,4'-di-R-2,2'-bipyridine; R = CF3, H, Me, tBu, OMe) complexes was prepared and studied for catalytic formic acid disproportionation. The relationship between the electron donating strength of the bipyridine substituents and methanol production of the corresponding complexes was analyzed; the unsubstituted (R = H) complex was the most selective for methanol formation.
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Complejos de Coordinación/química , Compuestos Férricos/química , Formiatos/química , Metanol/química , Catálisis , Complejos de Coordinación/síntesis química , Cristalografía por Rayos X , Conformación MolecularRESUMEN
Interventional clinical studies can provide the highest levels of evidence and generate significant results on specific investigational medicinal products or medical devices. In order to have powerful studies, attain unquestionable results and make significant discoveries, the number of patients enrolled must be high. Therefore, multinational, randomised clinical trials are necessary. The multicentre, multinational recruitment of subjects in investigator-initiated clinical trials (IICTs) increases their logistical burden, justifying the need for specific infrastructures to ease implementation. Herein, we provide for the first time an overview of the facts and figures concerning IICTs, existing infrastructures' capacity for interventional clinical research, and scientific performance of investigators in a European country, Portugal. We aim to highlight the relevance and need for investing in European infrastructures such as the European Clinical Research Infrastructure Network (ECRIN) for multinational IICTs. A public, non-profit organisation, ECRIN facilitates the conduct of multinational clinical trials in Europe by coordinating scientific partners and their networks, and providing advice, management services and tools to enhance collaboration. Currently in Portugal, few multinational randomised IICTs are coordinated by national investigators. This is most likely due to the lack of human resources dedicated to clinical trials in clinical research centres (CRCs) as well as the scarcity of professional academic clinical trial units (CTUs) providing logistics and management services at non-profit rates. With the data shown, we expect to trigger the development of similar studies in other European countries and stress the impact of government support for IICTs.
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Evaluating research outcomes requires multinational cooperation in clinical research for optimization of treatment strategies and comparative effectiveness research, leading to evidence-based practice and healthcare cost containment. The European Clinical Research Infrastructures Network (ECRIN) is a distributed ESFRI (European Strategy Forum on Research Infrastructures) roadmap pan-European infrastructure designed to support multinational clinical research, making Europe a single area for clinical studies, taking advantage of its population size to access patients, and unlocking latent scientific potential. Servicing multinational trials started during its preparatory phase, and ECRIN will now apply for an ERIC (European Research Infrastructures Consortium) status by 2011. By creating a single area for clinical research in Europe, this achievement will contribute to the implementation of the Europe flagship initiative 2020 'Innovation Union', whose objectives include defragmentation of the research and education capacity, tackling the major societal challenges starting with the area of healthy ageing, and removing barriers to bring ideas to the market.
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Investigación Biomédica/organización & administración , Evaluación de Resultado en la Atención de Salud/organización & administración , Ensayos Clínicos como Asunto , Europa (Continente) , Humanos , Cooperación InternacionalRESUMEN
BACKGROUND: The Directive 2001/20/EC was an important first step towards consistency in the requirements and processes for clinical trials across Europe. However, by applying the same rules to all types of drug trials and transposing the Directive's principles into pre-existing national legislations, the Directive somewhat failed to meet its facilitation and harmonization targets. In the field of ethics, the Directive 2001/20/EC conditioned the way of understanding and transposing the "single opinion" process in each country. This led to a situation in which two models of research ethics committees organisation systems exist, being the model in which the "single opinion" is considered to be the decision made by a single ethics committee more effective and simpler in terms of administrative and logistic workload. METHOD: A survey was conducted in 10 European countries. Members of the European Clinical Research Infrastructures Network working party number 1, with expertise in the field of ethics, responded. RESULTS: There is a major heterogeneity in the composition of ethics committees among the surveyed countries based on the number of members, proportion of experts versus lay members and expertise of the scientific members. A harmonized education of the ethics committees' membership based in common curricula is recommended by the majority of countries. CONCLUSIONS: Despite the efforts for harmonization of the European Clinical Trial Directive, from an ethical point of view, there remains a plurality of ethics committees' systems in Europe. It is important to comprehend the individual national systems to understand the problems they are facing.
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Comités de Ética en Investigación/organización & administración , Adhesión a Directriz/ética , Garantía de la Calidad de Atención de Salud/organización & administración , Ensayos Clínicos como Asunto , Conflicto de Intereses , Comités de Ética en Investigación/ética , Unión Europea , Humanos , Cooperación Internacional , Garantía de la Calidad de Atención de Salud/éticaRESUMEN
The aim of this study was to compare the clinical usefulness of ultrasmall superparamagnetic iron oxide (USPIO) MR contrast media (Sinerem, Guerbet Laboratories, Aulnay-sous-Bois, France) with precontrast MRI in the diagnosis of metastatic lymph nodes in patients with head and neck squamous cell carcinoma, using histology as gold standard. Eighty-one previously untreated patients were enrolled in a multicenter phase-III clinical trial. All patients had a noncontrast MR, a Sinerem MR, and surgery within a period of 15 days. The MR exams were analyzed both on site and by two independent radiologists (centralized readers). Correlation between histology and imaging was done per lymph node groups, and per individual lymph nodes when the short axis was > or = 10 mm. For individual lymph nodes, Sinerem MR showed a high sensitivity (> or = 88%) and specificity (> or = 77%). For lymph node groups, the sensitivity was > or = 59% and specificity > or = 81%. False-positive results were partially due to inflammatory nodes; false-negative results from the presence of undetected micrometastases. Errors of interpretation were also related to motion and/or susceptibility artifacts and problems of zone assignment. Sinerem MR had a negative predictive value (NPV) > or = 90% and a positive predictive value (PPV) > or = 51%. The specificity and PPV of Sinerem MR were better than those of precontrast MR. Precontrast MR showed an unexpectedly high sensitivity and NPV which were not increased with Sinerem MR. The potential contribution of Sinerem MR still remains limited by technical problems regarding motion and susceptibility artifacts and spatial resolution. It is also noteworthy that logistical problems, which could reduce the practical value of Sinerem MR, will be minimized in the future since Sinerem MR alone performed as good as the combination of precontrast and Sinerem MR.
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Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/patología , Medios de Contraste , Neoplasias de Cabeza y Cuello/patología , Hierro , Metástasis Linfática/diagnóstico , Imagen por Resonancia Magnética/métodos , Óxidos , Adulto , Anciano , Anciano de 80 o más Años , Dextranos , Femenino , Óxido Ferrosoférrico , Humanos , Metástasis Linfática/patología , Metástasis Linfática/ultraestructura , Nanopartículas de Magnetita , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , UltrasonografíaRESUMEN
RATIONALE AND OBJECTIVES: To evaluate the safety and pharmacokinetics of P792, a new macromolecular blood-pool agent for magnetic resonance imaging (MRI), in nonpatient volunteers. METHODS: This was a single blind, placebo-controlled, ascending-dose study in 32 healthy male volunteers, randomized to receive a single intravenous dose of P792 (0.0065, 0.013, 0.026, and 0.039 mmol/kg). The safety controls consisted of complete pre- and postdose physical examinations, measurement of vital signs, clinical laboratory investigations, and monitoring of adverse events (up to 22 days after injection). For pharmacokinetic analysis, the determination of P792 was performed using the ICP-MS technique for blood and urine samples up to 22 days. RESULTS: No serious adverse events occurred during the study. There were no clinically significant changes in vital signs, or clinical laboratory findings. P792 blood half-life, distribution volume, and renal clearance are consistent with the definition of a rapid clearance blood-pool agent (RCBPA) as defined previously. CONCLUSION: P792 appeared to be a safe and well-tolerated RCBPA in nonpatient subjects. Phase II studies will be conducted to evaluate the efficacy of the blood-pool agent for vascular, perfusion, and permeability imaging in MRI.
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Medios de Contraste/farmacocinética , Compuestos Heterocíclicos/farmacocinética , Imagen por Resonancia Magnética , Compuestos Organometálicos/farmacocinética , Análisis de Varianza , Área Bajo la Curva , Medios de Contraste/efectos adversos , Compuestos Heterocíclicos/efectos adversos , Humanos , Inyecciones Intravenosas , Modelos Lineales , Masculino , Compuestos Organometálicos/efectos adversos , Seguridad , Método Simple Ciego , Distribución TisularRESUMEN
Glomerular mesangial cells play a major role in the structure of capillary loops, generation of mediators of inflammation, and uptake of macromolecules. We demonstrate here that isobutylcyanoacrylate nanoparticles loaded with actinomycin D (ADNP) concentrate in rat mesangial cells in vitro and in vivo, as compared to the free drug (AD). In normal rats injected with 20 micrograms of 3H-ADNP or 3H-AD, the uptake ratios 3H-ADNP/3H-AD measured in whole kidneys at 30 and 120 min were 2.2 +/- 1.0 and 2.3 +/- 0.9, respectively. The same ratios calculated for isolated rat glomeruli and tubules, were 4.1 +/- 0.5 and 0.8 +/- 0.2 at 30 min, and 2.6 +/- 0.5 and 0.6 +/- 0.3 at 120 min, respectively. In the glomeruli, the absolute uptake of 3H-ADNP corresponded to 7.5 (30 min) and 1.8 (120 min)% I.D./100 mg of protein. In rats with experimental glomerulonephritis, the uptakes of 3H-ADNP and 3H-AD by the glomeruli were 6.9 and 4.0 times higher than in normal rats, respectively. In vitro experiments demonstrated up to 5 times higher uptake by glomerular mesangial cells than by epithelial cells. Uptake was maximum after 60 min, higher at 37 degrees C than at 4 degrees C, dependent on the presence of fresh serum and inhibited by cytochalasin-B. Drug targeting by nanoparticles is thus possible to renal cells involved in inflammatory processes, especially mesangial cells and macrophages. Nanoparticles could also be useful for lowering drug concentration in tubular cells, to reduce any tubular toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)
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Mesangio Glomerular/metabolismo , Animales , Células Cultivadas , Citocalasina B/farmacología , Dactinomicina/administración & dosificación , Dactinomicina/farmacocinética , Células Epiteliales , Epitelio/metabolismo , Mesangio Glomerular/citología , Mesangio Glomerular/ultraestructura , Glomerulonefritis/metabolismo , Microscopía Electrónica , Microesferas , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
The cytotoxicities of free cyanoacrylic nanoparticles, free Adriamycin, Adriamycin-loaded nanoparticles and a mixture of Adriamycin and nanoparticles are compared in cancer cell cultures. Increased cytotoxicity was observed in the sensitive (DC3F) subline when Adriamycin was in particulate form rather than free. In the derived pleiotropic resistant subline (DC3F AD/AZA), sensitivity to Adriamycin was completely restored with the conjugate. Addition of verapamil or amiodarone allowed an enhancement of efficiency of tenfold for free Adriamycin and between two- and fourfold for its conjugate form. Vectorization by nanoparticles and pharmacological modulation of cell membrane can act in synergy in synergy to overcome the resistance to Adriamycin in vitro.
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Cianoacrilatos , Doxorrubicina/toxicidad , Amiodarona/farmacología , Animales , Cricetinae , Cricetulus , Dactinomicina , Portadores de Fármacos , Resistencia a Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Biosíntesis de Proteínas , Células Tumorales Cultivadas , Verapamilo/farmacologíaRESUMEN
Subinhibitory doses of nystatin in the culture medium of Candida albicans gave yeasts with altered cell walls. Major alterations chiefly concerned the antigenic peptidomannans. Their amount in wall and their molecular weight were smaller in yeast grown with nystatin than in normal cultured yeast. Glucans and chitin were not seriously modified. Polymers requiring lipidic intermediates such as dolichol phosphate for their biosynthesis seemed to be most affected by the presence of nystatin.
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Candida albicans/efectos de los fármacos , Nistatina/farmacología , Aminoácidos/análisis , Candida albicans/crecimiento & desarrollo , Candida albicans/ultraestructura , Carbohidratos/análisis , Pared Celular/efectos de los fármacos , Fenómenos Químicos , Química , Mananos/análisis , Peso Molecular , Nistatina/administración & dosificaciónRESUMEN
Potato chips packaged in oriented polypropylene/low-density polyethylene/polyvinylidine chloride, high-density polyethylene/ethylene vinyl acetate plus a UV-light-absorbing compound, or high-density polyethylene/ethylene vinyl acetate plus a titanium dioxide light-barrier constructions developed distinct oxidized flavors within 7 d when stored at 21°C, 55% relative humidity, and under 140-230 ft candles of continuous fluorescent lighting. Potato chips stored under the same conditions that were packaged in a high-density polyethylene plus titanium dioxide and a brown light-absorbing pigment construction or an aluminum foil/polyethylene construction were stable throughout 10 weeks of storage. Oxygen-barrier film characteristics did not influence the oxidative stability of the air-packaged potato chips.