Population history of Corsica: a linguistic and genetic analysis.

Genetic and linguistic differentiations within Corsica were analysed and compared; the genetic relationships of Corsica to other Mediterranean populations were also studied. Lexical distances between 49 Corsican localities were computed from a standard word list; trees built from these distances were compared with average linkage and neighbour-joining trees of genetic distances. Our lexical distance results confirmed the north/south dialectal subdivision of Corsican speeches described by linguists. No clear results were achieved with genetic distances because of the low number of loci for which data were available. Nevertheless, a tight northern cluster clearly emerged. When compared to other Mediterranean populations, Corsica showed a certain degree of differentiation, although not so marked as that of Sardinia. Corsica presented genetic affinities with Campania, Sicily, Liguria, Provence and Latium, while distances with Tuscany and Sardinia were larger. These results can be interpreted as a reflection of the prehistoric isolation of Corsica and the relative contribution to the island gene pool of prehistoric and historic invaders and immigrants from several populations.

Screening for atopy in a coffee processing factory.

Screening for blood IgE mediated allergy (atopy) by the RAST technique among 76 people working in a coffee processing factory showed rather unexpected findings: although we found a prevalence of positivity (17.1%) to the common airborne antigens (pollens, mites, cat, Alternaria tenuis) which was close to the prevalence of atopy among normal adults in our area (19.3%), only one case of allergy to green coffee and two cases to castor bean came to the fore. Specific IgG4 antibodies were measured only for castor bean and green coffee, and rather elevated figures were found: green coffee 17.1%, castor bean 13.1%. The occurence of positive RASTs to castor bean is more likely to be due to contamination of the bags containing green coffee. The low prevalence of RAST positivities to green coffee, and the elevated specific IgG4 antibodies to both castor bean and green coffee antigens, raise several possibilities which are discussed; however, all the subjects but one having elevated specific IgG4 levels to green coffee worked in more exposed areas. Probably IgG4 antibodies in this particular case are acting as blocking antibodies.

Are the calcium antagonists really useful in cerebral aneurysmal surgery? A retrospective study.

From 1983 to 1990, 234 patients with one or several cerebral arterial aneurysms were surgically treated in our department. Since 1983, we have been performing surgery as early as possible. As soon as the subarachnoid hemorrhage diagnosis is confirmed by computed tomography (or if unconfirmed, by lumbar puncture), we assume that each patient may have an aneurysm. Between 1987 and 1990, 111 patients were treated by vascular volume expansion (maintenance of central venous pressure above 5 cm H2O with 4% albumin or Ringer-lactate or, if necessary, with 20% albumin), which we supplemented with calcium antagonists (nimodipine in 60 patients and nicardipine in 51 patients). Two months after being discharged, each patient is examined by a neurosurgeon and, on the same day, is subjected to a neuropsychological evaluation and a computed tomographic scan of the brain. A few months after this consultation, a working-position/family-activities questionnaire is issued to the patient. All of the results studied on the basis of postoperative mortality, second-month computed tomographic scan ischemia, neuropsychological evaluation, and return to work show no significant difference between the groups with or without calcium antagonists or between the nimodipine and nicardipine subgroups.

Prevalence of patent and latent atopy among a general normal adult population in the south east of France by RAST investigation and correlation with circulating total IgE levels.

A population of 512 adults (men: 266, 52%, women: 246, 48%) with mean age 41.4 years (S.D. 10.7) was investigated. This population was subdivided into five groups: Marseilles city, Manosque a small town in a prealpine area, the area surrounding the Etang de Berre, a rural area in Northern Bouches du Rhône and Chateaurenard, a small town in an intensive agricultural area. RASTs to a panel of eight allergens (Lolium perenne, Parietaria officinalis, Cupressus sempervirens, Olea europea, Cat dander, Alternaria tenuis, Dermatophagoides pteronyssinus, and Castor bean seed) were done. 99 subjects were found to have a RAST positive to one or several allergens. The main positives found by RAST were a grass pollen (Lolium perenne) and the mite Dermatophagoides pteronyssinus with respectively 10.1% and 11.3% of the results followed by the pollens of Olea Europea 4.4%, Parietaria officinalis 3.1% and Cupressus sempervirens 1.9%, Castor bean seed 1.7% Cat dander 0.9% and Alternaria tenuis 0.9%. Allergy to cstor bean (Ricinus communis) seed was found mostly in the Chateaurenard area where castor castor bean pomace is used in the fields as a fertilizer. There is an almost equal number of RAST positivities to mites (13.3%) than to pollens (11.1%). The prevalence of RAST positive was higher in men (24.1%) than in women (14.2%), p < 0.01). This prevalence is lower when age is increasing. Thirty four subjects (6.6%) had clinical symptoms: This group has a higher prevalence of positive RAST in cases of allergic rhinitis (p < 0.01) and of asthma (p > 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Screening for IgE mediated allergy among people working in the Marseilles harbour.

Screening for IgE mediated allergy by RASTs to professional (castor bean, green coffee, peanut, soy protein, wheat, rice), and non professional (pollens, mites, cat, Alternaria tenuis) air borne antigens among 36 people working in the Marseilles harbour has showed rather unexpected findings: only one case of IgE positivity to Dermatophagoides pteronyssinus (class I) and one case of IgE positivity to castor bean seed (Ricinus communis) (class IV). IgG4 specific antibodies against castor bean and green coffee were also measured by an ELISA technique, with eleven cases of positivity to castor bean and only one case to green coffee being recorded. Several explanations can be put forward for the low incidence of IgE responses to the commonest airborne antigens and to the professional antigens (castor bean being the only offender), and for the rather high incidence of specific IgG4 antibodies to castor bean. Most likely, the low incidence of latent atopy is the result of a natural selection among the workers who gave up their job if experiencing of discomfort. As far as the elevated IgG4 antibody levels to castor bean are concerned, these are probably natural blocking antibodies.