Essai préliminaire de détection des champs d'ambroisie par télédétection spatiale

The detection of dense populations of ragweed (Ambrosia artemisiifolia L.) using spatial remote sensing methods seems possible. A sufficiently accurate map of parcels of land infested with ragweed could offer new possibilities to engage in weeding campaigns and to appreciate the space-time evolution of this plant. Obviously, the main difficulties in this approach are related to the heterogeneous floral composition of herbaceous stands and to the risk of confusion of the spectral composition of ragweed with that of other species. On 21 July 2001, we carried out field surveys in zones with abundant ragweed near Lyon (Department of the Rhone), and we used the resulting data in connection with two images of the same area obtained by the Terra ASTER 1B satellite on 26 June and 13 August 2001. A measurement was made in the laboratory on a sample of the plant obtained from the same area to determine its reflectance spectrum. On analysis of the spatial images, we were able to localize herbaceous patches in which ragweed is dominant. When the density of this plant decreases, the reflectance signals of the populations become multiform, requiring further studies. Further progress can be expected when sensors such as the spatial tel IKONOS (operating at a resolution in the order of 1 to 5 m) or the future SPOT 5 (operating at a resolution of 2 to 3 m in the panchromatic mode or at 10 m in a multispectral mode) will be used, allowing us to work at a resolution on the order of one meter.     

Quand débuter et arrêter la désensibilisation aux venins d’hyménoptères ?

The efficacy of hymenoptera venom immunotherapy is well documented.The indication for this treatment is based on the history of a systemic allergic reaction to a sting by a honey bee or a vespid, the evidence for IgE-mediated allergy in skin tests or serologic examinations and our knowledge of the natural history of this allergy. The indication is given in the presence of a history of severe reaction with cardiovascular or respiratory symptoms and positive tests. Patients with mild to moderate reactions with predominant cutaneous symptoms and positive tests are only treated if they are heavily exposed and have developed repeated reactions. The optimal duration of venom immunotherapy has been analyzed in a number of prospective studies. In all of these the vast majority (> 80%) of those restung after discontinuation of an immunotherapy of at least 3 years’ duration was still protected. Relapses occurred more frequently in patients with a history of very severe pretreatment reaction and in those who developed systemic allergic symptoms during immunotherapy, either to treatment injections or to a sting by the insect in question. A treatment of 5 years was superior to a treatment of only 3 years. Therefore, a duration of 5 years is generally recommended, an even more prolonged treatment for patients with a history of very severe reactions or of allergic reactions during immunotherapy.     

Un cas d’encéphalomyélite aiguë disséminée post-infectieuse découvert devant une rétention vésicale fébrile

Introduction

MRI should be performed in the presence of an acute febrile urinary retention, when septic and obstructive causes are eliminated. We report a case of post-infectious probable acute disseminated encephalomyelitis (ADEM) with a mostly spinal cord tropism of involving Campylobacter.

Œdème insulinique au cours d’une glycogénose hépatique

Introduction

Hepatic glycogenosis is a rare syndrome, which includes poorly controlled diabetes mellitus, hepatomegaly, delayed puberty, and growth delay. Insulin edema is sometimes associated.

Présentation du Réseau d’Allergovigilance

The increased prevalence of food allergy and reports of allergy to novel foods led to the development of an “Allergy Vigilance Network.” This network is composed of 195 trained allergologists extending to 73% of the departments in France. Communications are carried out by e-mail or fax. The three objectives of this structure are: 1) to index the cases of lethal or prelethal anaphylaxis; 2) to evaluate the prevalence of food allergies, clinical pictures and allergens; and 3) to evaluate the allergic risk of novel foods. This network is composed of 195 allergologists as of 29 August 2001 (175 French, 11 Belgians, two from Fort-de-France, two from Luxembourg, one from Reunion island, one Greek, one Swiss, one Moroccan, two Poles). This network composed of trained allergologists appears to be essential in order to precisely evaluate the prevalence and allergic risk of food. It would be a helpful tool for public health organisms.     

Proposition d’un score prédictif d’infection bactérienne selon le taux d’éosinophiles : étude observationnelle

Introduction

Several studies have shown that eosinopenia less than 0.04 g/L is a marker of bacterial infection in the presence of unexplained inflammatory syndrome. The aim of our study was to test this hypothesis and to propose a predictive score for bacterial infection (score CIBLE, C reactive protein, bacterial infections, levels of leucocytes and eosinophils).