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 AGE (2011) 33:337-350 DOI 10.1007 Scientific knowledge on the subject The functional ventilatory consequences of the morphological and molecular changes in the carotid body observed in aged animals, as well as the ventilatory effects of dopamine and adenosine in old animals, are still unknown.What this study adds to the field The carotid body's peripheral control of ventilation is not impaired by aging. The preservation of the inhibitory and excitatory effects on ventilation caused by exogenous dopamine and adenosine, respectively, should be taken into account in the therapeutic use of these amines and their agonists and antagonists in elderly people. 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.

Purpose The pharmacology and clinical pharmacology and therapeutics (CPT) education during the undergraduate medical curriculum of NOVA Medical School, Lisbon, Portugal, was changed from a traditional programme (i.e. discipline-based, lectures) to a problem-based learning (PBL) programme (i.e. integrated, case-based discussions) without an increase in teaching hours. The aim of this study was to investigate whether this change improved the prescribing competencies of final-year medical students. Methods Final-year students from both programmes (2015 and 2019) were invited to complete a validated prescribing assessment and questionnaire. The assessment comprised 24 multiple-choice questions in three subdomains (working mechanism, side-effects and interactions/contraindications), and five clinical case scenarios of common diseases. The questionnaire focused on self-reported prescribing confidence, preparedness for future prescribing task and education received. Results In total, 36 (22%) final-year medical students from the traditional programme and 54 (23%) from the PBL programme participated. Overall, students in the PBL programme had significantly higher knowledge scores than students in the traditional programme (76% (SD 9) vs 67% (SD 15); p = 0.002). Additionally, students in the PBL programme made significantly fewer inappropriate therapy choices (p = 0.023) and fewer erroneous prescriptions than did students in the traditional programme (p = 0.27). Students in the PBL programme felt more confident in prescribing, felt better prepared for prescribing as junior doctor and completed more drug prescriptions during their medical training. Conclusion Changing from a traditional programme to an integrated PBL programme in pharmacology and CPT during the undergraduate medical curriculum may improve the prescribing competencies of final-year students.

No abstract

No abstract

No abstract

Dopamine has been widely used in humans in the management of cardiocirculatory shock, and its inhibitory effect on ventilation has received particular attention in clinical situations more prevalent in the elderly. Dopamine has been extensively studied at the carotid body in adult animals but little is known in aged animals. We investigated the ventilatory responses caused by dopamine in 3 and 24 months old rats.Cumulative intracarotid bolus injections of dopamine were performed in anaesthetised and vagotomised rats, in the absence and in the presence of i.v. infusions of domperidone (23.5-1175 nmol Kg(-1) min(-1)). Airflow (V), tidal volume (V(T)), respiratory rate (f), arterial blood pressure and heart rate were monitored and respiratory minute volume (V(E)) calculated. Basal values of V(E) were lower in 24 months rats (322.9+/-18.8 mL Kg(-1) min(-1)) than in 3 months old rats (442.5+/-24.2 mL Kg(-1) min(-1)), mainly due to reductions in V(T). The dose-dependent decreases caused by dopamine (3-100 nmol) in V(T), f and V(E), were totally prevented by section of the carotid sinus nerve and were not modified by ageing. The maximal % antagonism of the inhibitory effect of dopamine on V(E) caused by domperidone was similar in both 3 (74.6+/-2.7) and 24 (70.7+/-0.8) months old rats. Domperidone alone, increased basal V(E) by 59.6+/-16.6 mL min(-1) Kg(-1), and by 11.8+/-1.2 mL min(-1) Kg(-1), respectively in 3 and 24 months old rats (p<0.01).The inhibitory basal tonus caused by dopamine in ventilation was reduced in aged rats, although the decrease in V(E) caused by its exogenous administration remained unchanged.