Visits to the emergency room for asthma attacks and short-term variations in air pollution. A case-crossover study.

BACKGROUND: The 'case-crossover' design is a strategy fitted to studying transient effects of intermittent exposure on acute-onset disease occurring shortly after exposure. It has the important advantage of eliminating most confounding variables, allowing a stronger causality inference. OBJECTIVES: The objective of the study was to evaluate the relationships between emergency room (ER) visits for asthma attacks and gaseous air pollution changes. METHODS: The study included 549 individuals, 3-49 years old, visiting the ER during 1 year. Exposure to gaseous air pollutants (SO2, NO2, O3) on the same day and up to 4 days before was computed according to the patient's address. The statistical analysis included meteorological data as potential confounding variables. RESULTS: No association could be shown between ER visits and SO2 or NO2 levels. In contrast, there was a statistically significant association between ER visits and mean O3 levels, on the day of admission and also on D -2 and D -3. For an increase of 10 microg/m3, the risk of requiring an ER admission increased by 6-10%. CONCLUSIONS: Using this new strategy, we confirmed that ozone changes lead to a moderate increase in risk of requiring an ER admission in asthmatic subjects.

[Gastric lactobezoar in an infant induced by Gelopectose]. / Lactobézoard gastrique du nourrisson induit par Gélopectose.

We report an observation of intragastric lactobezoar secondary to the use of thickened feeding by adding pectin and silicium to milk. Medical management resulted in a favourable outcome.

[Upper extremity abnormalities, thrombopenia and thrombopathy. 3 cases]. / Anomalies du membre supérieur, thrombopénie et thrombopathie. A propos de trois observations.

Three cases of congenital radial aplasia and amegakaryocytic thrombopenia are discussed from clinical, genetic and hematological viewpoints. Electron microscope studies of the megakaryocytes in the first two patients revealed the presence of microcytic, immature and hypogranular cells. Platelet aggregability studies in the first patient demonstrated the presence of pathological intra-platelet nucleotide release as well as membrane abnormalities of the Willebrand factor binding site. The second case presented an isolated deficiency in platelet factor 3.