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1.
BMJ Open ; 9(5): e023394, 2019 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-31092640

RESUMEN

OBJECTIVES: This study aims to identify the sources of funding for investigator-initiated clinical trials (IICTs) in Portugal, and to recommend ways to improve the quality of information collected from clinical trial databases about funding. DESIGN AND METHODS: A systematic search of trial registrations over the last 13 years-using the WHO International Clinical Trials Registry Platform (WHO-ICTRP) and four clinical trials registries (CTRs)-was carried out to identify IICTs in Portugal, used as a case study. Data from the databases were compared with data contained in publications to evaluate the consistency of information on funding sources. The term 'database' is used in this study to refer to both the WHO-ICTRP and the CTRs. When mentioned separately, the WHO-ICTRP is referred to as a 'platform', while the CTRs are referred to as 'registries'. OUTCOME: Suggestions to improve clinical trials databases to clearly identify the funding sources and data ownership in IICTs. RESULTS: Two hundred and eighty-two IICTs were identified in Portugal. Twenty per cent of trials were supported by industry with unclear information on the ownership of the results. Inaccuracy was found in the information about sponsors and funders. The information about funding in all resulting publications (77 out of 133 completed studies) was also inconsistent between databases in 35 out of 77 (45%) of the studies. Notably, 23% of the trials funded by non-profit organisations (n=226) received funds from international and/or national funding agencies. CONCLUSIONS: Identification of IICT funding and ownership of results is unclear in the databases used for this study, which may lead to misunderstandings about the independence of the obtained results. Transparency and accuracy are desirable so that public decision makers and strategic partners can accurately evaluate national performance in this particular type of clinical research.


Asunto(s)
Investigación Biomédica/economía , Ensayos Clínicos como Asunto/economía , Recolección de Datos , Bases de Datos Factuales , Humanos , Portugal , Reproducibilidad de los Resultados , Apoyo a la Investigación como Asunto
2.
Age (Dordr) ; 33(3): 337-50, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20922488

RESUMEN

The carotid body (CB) is the main arterial chemoreceptor with a low threshold to hypoxia. CB activity is augmented by A(2)-adenosine receptors stimulation and attenuated by D(2)-dopamine receptors. The effect of aging on ventilatory responses mediated by the CB to hypoxia, ischemia, and to adenosine and dopamine administration is almost unknown. This study aims to investigate the ventilatory response to ischemia and to adenosine, dopamine, and their antagonists in old rats, as well as the effect of hypoxia on adenosine 3',5'-cyclic monophosphate (cAMP) accumulation in the aged CB. In vivo experiments were performed on young and aged rats anesthetized with pentobarbitone and breathing spontaneously. CB ischemia was induced by bilateral common carotid occlusions. cAMP content was measured in CB incubated with different oxygen concentrations. Hyperoxia caused a decrease in cAMP in the CB at all ages, but no differences were found between normoxia and hypoxia or between young and old animals. The endogenous dopaminergic inhibitory tonus is slightly reduced. However, both the ventilation decrease caused by exogenous dopamine and the increase mediated by A(2A)-adenosine receptors are not impaired in aged animals. The bradycardia induced by adenosine is attenuated in old rats. The CB's peripheral control of ventilation is preserved during aging. Concerns have also arisen regarding the clinical usage of adenosine to revert supraventricular tachycardia and the use of dopamine in critical care situations involving elderly people.


Asunto(s)
Adenosina/farmacología , Envejecimiento/fisiología , Cuerpo Carotídeo/fisiología , Dopamina/farmacología , Hipoxia/fisiopatología , Isquemia/fisiopatología , Antagonistas del Receptor de Adenosina A2/farmacología , Animales , Cuerpo Carotídeo/irrigación sanguínea , Cuerpo Carotídeo/química , Cuerpo Carotídeo/efectos de los fármacos , AMP Cíclico/fisiología , Modelos Animales de Enfermedad , Antagonistas de Dopamina/farmacología , Masculino , Ventilación Pulmonar/efectos de los fármacos , Ventilación Pulmonar/fisiología , Ratas , Ratas Wistar , Receptor de Adenosina A2A/metabolismo
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