[Measuring pulse oximetry at the patient's bedside]. / Mesurer l'oxymétrie de pouls au lit du malade.

Pulse oximetry, or oxygen saturation, reflects the quantity of oxygen fixed to the haemoglobin. It is commonly measured in a non invasive way, with the aid of a digital sensor oximeter. The results can be distorted by a number of parameters, it is therefore necessary to eliminate the risk of errors and to check the results against clinical data.

Airway ion transport impacts on disease presentation and severity in cystic fibrosis.

OBJECTIVES: Abnormal airway ion transport is a feature of cystic fibrosis. The aim of this study was to investigate whether distinct components of ion transport are associated with the clinical expression and severity of the disease. DESIGN AND METHODS: Univariate and multivariate analyses were used to study interaction effects between nasal potential difference parameters and clinical status, recorded at stable conditions, in 75 F508del homozygous young adults. RESULTS: All patients demonstrated increased sodium and reduced chloride conductances. Less sodium transport abnormalities were related to better respiratory function and nutrition. Presentation with digestive symptoms at diagnosis was associated with lower chloride conductance. With an accuracy of 85% good nutritional status was linked to more preserved lung function, increasing age and more preserved chloride conductance. CONCLUSIONS: Ion transport abnormalities have distinct clinical outcomes. Sodium conductance relates to respiratory function and nutrition; chloride conductance to nutrition and presentation with digestive symptoms at diagnosis.

Mitochondrial membrane potential: a novel biomarker of oxidative environmental stress.

Epidemiologic analyses, traditionally based on long-term cohort or case-control studies, provide retrospective causal associations between exposure to a particular environmental stressor and an exposure-related disease end point. Recent research initiatives have propelled a shift toward exploring molecular epidemiology and molecular biological markers (biomarkers) as a means of providing more immediate, quantitative risk assessment of potentially deleterious environmental exposures. We compared, in normal human monocytes isolated from the blood of healthy donors, variations in Hsp70 expression and mitochondrial membrane potential (delta psi m) in response to exposure to either tobacco smoke or gamma-irradiation, two models for environmentally mediated oxidant exposure. On the basis of its mechanistic specificity for oxidants and little baseline variation in cells from distinct individuals, we propose that delta psi m represents a selective in vitro and in vivo biomarker for oxidant exposure. delta psi m may be used to gauge risks associated with oxidant-mediated air pollution and radiation.