Articles: cross-over-studies.
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Drug Metab. Pharmacokinet. · Jan 2002
Application of in vivo brain microdialysis to the study of blood-brain barrier transport of drugs.
Recent advances in blood-brain barrier (BBB) research have led to a new understanding of drug transport processes at the BBB. The BBB acts as a dynamic regulatory interface at which nutrients necessary for neural activity are actively taken up into the brain from the blood circulation, and actively excludes metabolites that might interfere with the maintenance of brain homeostasis. Such influx and efflux transport functions at the BBB would also control the concentrations of various drugs in the brain interstitial fluid (ISF), which are an important determinant of the central nervous system (CNS) effects. ⋯ Although several experimental techniques have been developed to investigate transport functions across the BBB, in vivo brain microdialysis seems to be one of the most suitable techniques for characterizing the influx and efflux transport functions across the BBB under physiological and pathological conditions. This review covers studies during the past decade, in which the influx and efflux transport of drugs across the BBB was kinetically and mechanistically evaluated by means of the brain microdialysis technique. Some applications of brain microdialysis to studies on neuronal function and neurotherapeutics are also included.
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The case-crossover study design is a popular analytic tool for estimating the effects of triggers of acute outcomes by environmental exposures. Although this approach controls for time-invariant confounders by design, it may allow for selection bias and confounding by time-varying factors. We conducted a simulation study of the sensitivity of the symmetric bidirectional case-crossover design to time-varying patterns in exposure and outcome. ⋯ Confounding results from a common temporal pattern in the exposure and the outcome time series, but can also be the result of patterns in exposure and outcome that, although asymptotically uncorrelated, are correlated at finite series lengths. All three biases are reduced by choosing shorter referent-spacing lengths. This effect is illustrated using data on air pollution and daily deaths in Chicago.
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To estimate the level of knowledge that Canadian emergency physicians have of the costs of common diagnostic tests and interventions in the emergency department (ED). ⋯ Emergency physicians have a limited knowledge of the costs of the tests and interventions they use on a daily basis. They tend to overestimate lab and pharmaceutical costs but underestimate imaging costs. Cost-awareness programs for emergency physicians are most likely to be beneficial if they focus on imaging modalities.
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Journal of anesthesia · Jan 2000
Randomized Controlled Trial Clinical TrialEffects of sevoflurane compared with those of isoflurane on arterial oxygenation and hemodynamics during one-lung ventilation.
This study was designed to compare the effects of sevoflurane and isoflurane on Pao(2) and hemodynamic variables during one-lung ventilation (OLV) in surgical patients. ⋯ The effects of sevoflurane on PaO(2) and the hemodynamic variables were similar to those of isoflurane during TLV and OLV in the lateral decubitus position.
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Subjective well-being is an essential ingredient in the quality of life concept. The Marburg questionnaire, a seven item scale for the assessment of the trait dimension of well-being, claims to possess good psychometric properties. This is investigated in two studies with chronic pain patients. ⋯ The good psychometric quality of the questionnaire along with its brevity allows its application as part of a quality of life assessment.