Biodynamic study of americium-241 accumulation in the cytosol of the hepatopancreas of the lobster Homarus gammarus.

In the lobster, most of the radionuclides ingested with contaminated food are concentrated in the digestive gland. Americium-241 accumulation in the hepatopancreas of the lobster was studied during the digestive cycle. Fractionations of cytosols at different times after ingestion of radioactive preys were performed by gel permeation chromatography to determine the distribution of 241Am in the different macromolecular components. 241Am was associated with ferritin during the whole digestive cycle. This observation suggests a correlation between 241Am distribution pathways and iron metabolism. The distribution of 241Am present in the other cytosolic proteins followed two major steps of accumulation which may be correlated to the evolution of the two main cellular types playing an important role in the digestive cycle (B and R type cells).

Chemical behaviour of three radionuclides (cesium, americium and technetium) and their uptake at the cytosolic level in aquatic organisms.

In previous papers, we observed that there were great differences in the subcellular accumulation and elimination of 137Cs, 99Tc and 241Am in different marine animals. In this study, we analysed and compared the behaviour of these radionuclides at the cytosolic level. We found great similarities in the cytosolic distribution of a given radionuclide in the various organisms studied. The chemical characteristics of the radionuclides seem to play a major role in the biochemical affinity and metabolic behaviour in different aquatic organisms.

Distribution of [241Am] in hepato-pancreatic nuclear proteins of the lobster (Homarus gammarus).

Recent studies on the bio-accumulation of transuranic elements in marine invertebrates have demonstrated an intracellular concentration of radionuclides in the digestive gland. The present investigation aims to establish the distribution of [241Am] within the different structures of the cell nucleus. Lobsters were experimentally contaminated through feeding and then killed. The nuclei of hepato-pancreatic cells were isolated, purified and dissociated. The different protein categories were separated in media of increasing ionic strength. The distribution of americium in this material yielded results showing a preferential fixation onto the structural proteins of the nuclear matrix. The radiological consequences of such an affinity are discussed in terms of the life-times of the ligands concerned.

[Ambulatory anesthesia in pediatrics. 2-year experience of performance at a day hospital]. / Anesthésie ambulatoire en pédiatrie. Expérience de deux années de fonctionnement d'un hôpital de jour.

Ambulatory pediatric anaesthesia is done within a well-organized medical and surgical structure. The anaesthesia consultation confirms the surgical indications, taking into account certain medical pathologies. 27% of elective surgery is done in day-hospital. The anaesthetic techniques described have been done in children from three weeks to sixteen years of age. Intubation was not an exclusion criterion. The major causes for transfer to the general hospital (2.9%) are given. Anaesthetic complications represent 0.1% of such transfers. Scrupulous respect of the selection criteria, competence of anaesthesiologists and of pediatric surgeons are prerequisites for good results.

[Bronchial response to allergens after controlled NO2 exposure (author's transl)]. / Réponse bronchique aux allergènes après exposition controlée au dioxyde d'azote.

The bronchial response to inhaled grass pollen (assessed by specific airway resistance, SRaw, measurements) was determined in seven allergic patients after each had spent 1 hour in an exposure chamber breathing on one occasion unpolluted air and on a separate occasion (one week interval) a mixture of air and nitrogen dioxide (NO2, 207 micrograms/m3). Sequences of exposure to unpolluted air and to NO2 were randomized in a single-blind fashion. No significant change in baseline SRaw or in the response to antigen was observed after NO2 exposure.