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Biomedical subjects

A Lafontaine

Publications and source records attributed to A Lafontaine.

At least 19 recordsLinked to original sources

[Epidemiology of "stress" and the problems it poses in the medical and social fields. The special case of acute psychic reactions to psychologic trauma].

It is important to distinguish clearly between the terms "stress" and the "breakdown in adaptation" which can result therefrom. Stress may be defined as the alert response of the organism to physical and psychological aggression. We need to expand our knowledge about the physiological and pathological reactions which occur at the onset of stress and study the importance of disturbances thus engendered. The direct and indirect consequences of stress and breakdown in adaptation also require evaluation not only from the general and occupational medicine viewpoint, but also sociologically. At the same time, research should be carried out on ways of avoiding--or at least limiting--the damaging consequences of exposure to stress-inducing situations, and on establishing effective preventive or corrective treatment. Special attention should be given to acute psychotraumatism.

Acute Disease↗

Some thoughts on a possible regulatory approach at EEC level on the classification and labeling of dangerous preparations.

At the present time no European directives on classification, packaging, and labeling exist which cover all dangerous preparations of chemicals. To develop such a directive, the Commission of the European Economic Community services, at the request of and in close collaboration with experts of the member states, has conceived a method for evaluating the toxicity of mixtures of chemicals. This method consists of (a) the characterization of each constituent by means of an index and (b) the classification of preparations for each route of administration on the basis of their toxicity. The index is a figure representing the degree of dilution needed to render the substance not dangerous in the sense of the EEC Directives on the classification of dangerous substances; the highest index among those obtained for acute and chronic toxicity is taken to characterize the substances. An indication of toxicity is obtained by applying the simple equation sigma (P X I), where P is the percentage and I is the index of each constituent. The most stringent classification among those obtained for the three routes of administration is taken for the final classification of the preparation on the basis of its acute and chronic toxicity. Other toxicological effects such as irritation, corrosion, sensitization, mutagenesis, teratogenesis, and carcinogenesis are not considered.

Animals↗

Exposure to lead of the Belgian population.

According to the Council Directive of 29 March 1977 on biological screening of the population for lead, the blood-lead levels (PbB) were determined in samples of the Belgian population not occupationally exposed to this metal. Two campaigns of sampling were performed: the first one in 1979 (1678 samples analysed) and the second in 1981 (1000 samples analysed). Sampling was done in urban and industrial zones, as well as in areas where lead risk could be present. Concerning the urban and industrial areas, the results obtained seem to indicate that a particular lead risk does not exist for the adult population if we consider the reference levels of the CEE Directive. Moreover, the results of the second campaign of sampling showed a decreasing trend: the median PbB values dropped from 183 to 156 micrograms/l in Brussels and from 192 to 139 micrograms/l in Liège. This could be partly due to the limitation of the lead content of gazoline. On the other hand, the results of the surveys clearly demonstrated the existence of two areas where an obvious lead risk exists. In one of those, the lead risk is of industrial origin (lead smelter) and concerns mainly children: median PbB value 260 micrograms/l, percentile 90 and 98 respectively 390 and 430 micrograms/l. In the other one, the lead risk is from a hydric source and concerns adults and children: median PbB value 258 micrograms/l, percentile 90 and 98 respectively 370 and 520 micrograms/l.

Adult↗

Exposure to lead and cadmium of the general population of Malta.

The blood levels of lead (PbB), cadmium (CdB), and zinc protoporphyrin (ZPP) were determined in 538 Maltese adult subjects. A relatively high level exposure to both metals was discovered. For lead, the median value is 274 micrograms/l with percentile 90 and 98 respectively 564 and 863 micrograms/l. These values are to be compared with the reference values proposed by a directive of the European Community, respectively 200, 300 and 350 micrograms/l. For cadmium, the median value is 2.2 micrograms/l with percentile 90 and 98 respectively 3.8 and 5.7 micrograms/l. These values are compared with those of a Belgian population which are respectively 1.7, 2.6 and 4.3 micrograms/l. The causes of this relatively high exposure are not known. A few tentative hypotheses, which are to be investigated, are made.

Adolescent↗

Longitudinal study of asymptomatic meningococcal carriage in two Belgian populations of schoolchildren.

In Brussels, a 15-month longitudinal survey was conducted in two primary schools, from March 1975 to May 1976, in order to analyse the dynamic of asymptomatic meningococcal carriage, during an epidemic mainly caused by serogroup B, serotype 2 Neisseria meningitidis. In the first school, which is situated in a suburban area with upper-middle socio-economic status of residents, a mean prevalence of carriers of 10 per cent, an acquisition rate of eight per 1000 months, and a mean duration of carriage of 12.4 months were observed among 158 schoolchildren aged six to 11 years old. In the second school, which is situated in a densely populated area with low socio-economic status of residents, a mean prevalence of carriers of 33 per cent, an acquisition rate of 28 per 1000 months, and a mean duration of carriage of 11.7 months were observed among 203 schoolchildren aged three to 14 years old. For both schools, the median duration of carriage was estimated at 9.4 months. The differences of prevalence and incidence of acquisition between the two schools cannot be explained by age, sex or ethnic factors and are probably related to socio familial variables. The theoretical relationship between prevalence, incidence and duration of meningococcal carriage was for the first time demonstrated in this study. The results also suggest that populations of low socio-economic status and living in densely populated areas constitute a target population for meningococcal disease prevention.

Adolescent↗