RESUMO
BACKGROUND: The degree of difficulty we experience while learning different concepts and skills depends, among other things, on our psychological features and learning style. This may be particularly true for medical students, whose formation involves the acquisition of multiple cognitive, affective and psychomotor skills. AIM: To assess whether the psychological features and learning styles of medical students are associated with their academic performance. SUBJECTS AND METHODS: The psychological preferences and learning styles of 66 students of the 2001-graduating cohort were determined with the Myers Briggs Type Inventory (MBTI) and the Kolb Learning Style Inventory (LSI), respectively. The academic performance was assessed by the Calificación Médica Nacional (CMN), Chile and by the marks obtained during the Basic (1st to 3rd), Preclinical (4th and 5th) and Clinical (6th and 7th) years of undergraduate training. RESULTS: The psychological features, together with the sex of students were found to be associated with the performance in the Preclinical and Clinical years, and to the CMN. In men, the interest and ability to communicate with people and the concern for harmony, and in women the tendency to function in a systematic and orderly way are the features associated to high academic performance. No associations were found between learning styles and academic performance. CONCLUSIONS: The finding that the psychological preferences of medical students are relevent to their academic performance opens a new perspective to analyze the medical education and to design programs aimed at improving learning.
Assuntos
Feminino , Humanos , Adulto , Masculino , Educação de Graduação em Medicina , Aprendizagem , Avaliação Educacional , Estudantes de Medicina/psicologia , Extroversão Psicológica , Chile , Estatística , Estudos Longitudinais , Estudos Retrospectivos , Fatores Sexuais , Introversão PsicológicaRESUMO
BACKGROUND: Psychological type and learning style influence the way students perceive and process information. However, research in medical education in Chile still does not put enough emphasis in the study of these variables. AIM: To characterize the psychological types and learning styles of the students admitted to a Medical School. SUBJECTS AND METHODS: The Myers Briggs Type Indicator (MBTI) and the Kolb's Learning Styles Inventory (IEA) were administered to the 270 students admitted from 2000 to 2002 to the medical school of the Pontificia Universidad Católica de Chile. RESULTS: Fifty five percent of our students are concentrated in 4 of the 16 psychological types described. These students are characterized by the ability to base their decisions upon logical and objective reasoning (Thinking [T]) and to face life in a structured and decided way (Judging [J]). Only 10 per cent of the students have preferences opposite to T and J. These students base their decisions on the preservation of harmony and teamwork (Feeling [F]) and have a flexible attitude towards life (Perceiving [P]). The remaining 35 per cent have types with pairs of preferences TP and FJ. With regard to learning styles, more than two thirds of our students are Assimilators or Convergers. These learners tend to assimilate large amounts of information and abstract the main concepts, rather than to pay attention to concrete details. In general, our students are more reflective than active; they evaluate thoroughly all alternatives before making a decision. CONCLUSIONS: The psychological types and learning styles of medical students cluster around specific patterns whose features may either favor or hamper a specific learning. Knowledge of the differences in psychological types and learning styles of students may provide teachers with a new and valuable tool for improving learning and contributing to the academic success of students.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Educação de Graduação em Medicina , Aprendizagem , Estudantes de Medicina/psicologia , Extroversão Psicológica , Chile , Introversão PsicológicaRESUMO
We aimed at characterizing the receptor subtype and the signaling pathway involved in the inhibitory effect of neuropeptide Y on the release of endogenous noradrenaline from rat hypothalamus. Slices of hypothalamus were stimulated with two trains of electrical pulses, and the release of noradrenaline and nitric oxide was measured. The electrical stimulation of hypothalamic slices induced a consistent release of both endogenous noradrenaline and NO. Neuropeptide Y inhibited concentration dependently the stimulated noradrenaline release. Similarly, agonists for neuropeptide Y Y1, Y2 and Y5 receptors inhibited noradrenaline release, albeit with a potency lower than neuropeptide Y. GW1229, a selective neuropeptide Y Y1 receptor antagonist counteracted the effect of neuropeptide Y, but not that of PYY-(3-36), an agonist active at neuropeptide Y Y5 and Y2 receptors. These results indicate that the inhibitory effect of neuropeptide Y is likely mediated by several receptor subtypes, including neuropeptide Y Y1, Y5 and possibly Y2 receptors. One microM NPY significantly enhanced NO release induced by the electrical stimulation. NG-monomethyl-L-arginine, an inhibitor of nitric oxide synthase, abolished NO release and blocked the inhibitory effect of neuropeptide Y on noradrenaline release. We conclude that nitric oxide participates in the signaling pathway of neuropeptide Y in the rat hypothalamus.
Assuntos
Hipotálamo/efeitos dos fármacos , Neuropeptídeo Y/farmacologia , Óxido Nítrico/metabolismo , Norepinefrina/metabolismo , Receptores de Neuropeptídeo Y/efeitos dos fármacos , Animais , Estimulação Elétrica , Hipotálamo/metabolismo , Masculino , Oligopeptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Neuropeptídeo Y/antagonistas & inibidores , Receptores de Neuropeptídeo Y/metabolismoRESUMO
We studied the effect of GW1229, a novel neuropeptide Y Y1 receptor antagonists, on the vasoconstriction induced by neuropeptide Y and structurally related analogs in the hamster cheek pouch microcirculation. Changes in arteriolar diameter and microvascular conductance were assessed by intravital microscopy and measurement of sodium22 clearance. GW1229 did not affect basal vascular conductance but inhibited, concentration dependently, the reduction in arteriolar diameter and vascular conductance induced by 100 nM neuropeptide Y. GW1229 also counteracted the vasoconstrictor effect of 100 nM [Leu31,Pro34]neuropeptide Y, and that of 300 nM neuropeptide Y-[(13-36). In contrast, GW1229 had no effect on the vasoconstriction induced by noradrenaline. We conclude that the vasoconstrictor effect on neuropeptide Y in the hamster cheek pouch is mediated by neuropeptide Y Y1 receptors. The maintenance of physiological tone in this vascular bed does not involve the participation of endogenous neuropeptide Y.
Assuntos
Neuropeptídeo Y/antagonistas & inibidores , Oligopeptídeos/farmacologia , Receptores de Neuropeptídeo Y/antagonistas & inibidores , Vasoconstrição/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Cricetinae , Masculino , Mesocricetus , Microcirculação/efeitos dos fármacos , Dados de Sequência Molecular , Norepinefrina/farmacologiaRESUMO
To determine whether the release of tritiated noradrenaline (NA) from the sympathetic nerve terminals of the rat vas deferens is an accurate reflection of the release of endogenous NA, we compared the electrically-evoked release of tritiated and endogenous NA from the prostatic sections of the vasa deferentia of male rats. We found that while the release of tritiated NA was completely dependent on the presence of calcium, the release of endogenous NA was not. The overflow of both, tritiated and endogenous NA, was virtually unaffected by blockade of the neuronal uptake mechanism by desipramine. In contrast, blockade of the extraneuronal uptake greatly increased the overflow of endogenous NA, while having no effect on the overflow of tritiated NA. Tritiated NA release, on the other hand, was sensitive to prejunctional regulation, while the release of endogenous NA was not. Increases in stimulus train duration induced a significant increase in the release of endogenous NA, but not in that of tritiated NA. In contrast, the later responded to lower stimulus train frequencies and reached a plateau at lower frequency values as compared to the endogenous NA release. Our results indicate the existence of marked differences between the release of tritiated and endogenous NA. We conclude that: 1) the assumption that tritiated NA release provides a good marker for endogenous NA release in the rat was deferens seems unwarranted; 2) the use of endogenous NA to study the release process in the vas deferens requires a re-examination of the experimental conditions used, in order to minimize possible artifacts that may obscure the study of neuronal release; 3) the choice between measuring the release of tritiated or endogenous NA must be evaluated for each tissue in particular, taking into account its cytoarchitecture, as well as the experimental conditions used.
Assuntos
Norepinefrina/metabolismo , Sistema Nervoso Simpático/metabolismo , Ducto Deferente/inervação , Animais , Cádmio , Estimulação Elétrica , Masculino , Ratos , Ratos Sprague-Dawley , Simpatomiméticos/metabolismo , TrítioRESUMO
The purpose of the present investigation was to ascertain the functional significance of the reduction in cyclic AMP (cAMP) levels in the inhibitory action of neuropeptide Y (NPY) on [3H]noradrenaline ([3H]NA) release, as well as to further characterize the subtype(s) of NPY receptors involved in the peptide's actions in the rat vas deferens. We studied the effects of NPY, carboxyterminal fragments of this peptide and the NPY analog (Leu31,Pro34)-NPY on three functional responses, namely, the release of [3H]NA and the associated muscle contractions evoked by electrical stimulation, and the accumulation of cAMP stimulated by forskolin. NPY, a known inhibitor of the electrically-evoked [3H]NA release and neurogenic contractions is also a potent inhibitor of the forskolin-stimulated cAMP synthesis in the prostatic portion of the rat vas deferens. However, the ability of NPY to inhibit cAMP accumulation is lost upon tissue denervation, suggesting that this is likely to be a prejunctional effect. Elevation of cAMP levels by the use of the cell permeant analog of cAMP, 8-(p-chlorophenylthio)-cAMP (8pCPTcAMP) increases the electrically-evoked release of [3H]NA. However, the inhibition of [3H]NA release by NPY is not prevented by 8pCPTcAMP. Structure-activity relationship studies reveal that NPY and related peptides inhibit the release of [3H]NA, the muscle contractions and the synthesis of cAMP with a similar pharmacological profile. NPY is the most potent inhibitory agent, whereas [Leu31,Pro34]-NPY and NPY13-36, the respective Y1 and Y2 selective agonists, display similar potencies to inhibit the three responses. It is concluded that NPY inhibits neurotransmission in the rat vas deferens through the activation of a peptide receptor different from the known NPY-Y1 or NPY-Y2 receptor subtypes. NPY receptor activation in the vas deferens is negatively coupled to adenylyl cyclase activity. This intracellular signalling pathway is, however, not likely to mediate the peptide effects on the prejunctional regulation of noradrenaline release.