Effets produits chez trois espèces de criquets par l'ingestion d'hydrocarbures polyaromatiques réputés cancérogènes

In a first approach to studying the effects of air pollutants, we describe some experimental results obtained after ingestion of polyaromatic hydrocarbons (HAP)^* by three species of locusts (Gomphocerus sibiricus, Gomphocerus rufus and Euchorthippus pulvinatus). We wanted to evaluate their toxicity, then to locate them in the organism. Two HAP, carcinogenic for mammals, were used. They are highly toxic for our locusts. Ingestion of 0.015 or 0.06 mg of 3 methylcholanthrene kills respectively 25 % and 50 % of them. Moreover, benzo-a-pyrene seems to have a greater toxicity, and E. pulvinatus is the most resistant species. Strongly fluorescent in UV light, 3 MC and BaP can be easily detected in the organism after dissection, and with more detail using frozen material. The microscope shows absorption activity of midgut; most of the organs are consequently invaded by intact hydrocarbon or its various derivatives. Muscles and reproductive organs show a bright fluorescence, which reaches its maximum in the nervous system. Tubes of Malpighi seem to be the principal route of elimination of these products. The remarkable susceptibility of some organs is encouraging for the progress of our study.     

Profil lipidoprotéinique,isotopique et risque athérogène dans la drépanocytose en Côte d’Ivoire

The principal goal of this study was to assess the possible disturbances of lipids and lipoproteins in sickle cell disease and establish a relationship between painful crisis and atherogenic risks by the atherogenicity index in Ivoirian adults. We analysed serum plasma lipid and lipoprotein profiles of 126 subjects with sickle cell anemia, and 55 “Hb AA” healthy individuals. The lipid and lipoprotein parameters studied were total cholesterol, triglycerids, HDL, LDL, apoproteins A1 and B, electrophoresis of lipoproteins and haemoglobin. In painful crisis, levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, apoproteins A1 (apo A1) in sickle cell anemia patients were shown to be significantly lower and levels of triglycerides higher than that of control group and steady state. The electrophoresis profile showed a significant fall of α lipoproteins while β lipoproteins were significantly high in period of crisis. The atherogenicity index (total cholesterol/HDL ratio) was also significantly high, just as LDL/HDL ratio in period of crisis. The overview of these results might hypothesize a high relatively atherogenic risk during the sickle-cell anemia crisis. A special monitoring of the patients in crisis is also necessary in order to prevent the risk of cardiovascular diseases.     

Les gangrènes des organes génitaux externes: à propos de 102 cas

Objectives

To describe the epidemiological, clinical, biological and therapeutic features of Fournier’s gangrene and identify the prognostic factors.

Patients and methods

We conducted a retrospective study on 102 cases of Fournier’s gangrene treated at the urology department of the university teaching hospital Aristide- Le-Dantec (Dakar) between January 2001 and December 2007.

Results

The mean age of the patients was 50.0 ± 15.7 years (range: 20–93 years). The mean duration of hospital stay was 8.0 ± 7.1 days (range: 1–33 days). The lesions were located on the scrotum in 61.7% of cases, on the scrotum and penis in 17.6% of cases and on the penis alone in 3.9% of the cases. Perineal involvement was found in 14.7% of the cases. No etiologic factors (idiopathic) were found in 26 cases (25.5%) and 70 patients (68.6%) had Fournier’s gangrene secondary to urethral stricture. The most common predisposing factors were diabetes mellitus (13.7%), hypertension (5.9%), and renal failure (5.9%). Biological examination revealed that 79.4% of patients had a leukocytosis higher than 12,000/ml and the mean rate of haemoglobin was 9.8 ± 2.8 g/dl (range: 3.3–13.9 g/dl). The most common antibiotherapy associated a third generation cephalosporin, aminoside and metronidazole (46.1%). Twenty-one patients (20.6%) underwent extensive debridement only and eighty-one (79.4%) underwent extensive debridement and cystostomy. The death rate was 15.7%. Among the patients whose Fournier’s gangrene was idiopathic or secondary to urethral stricture, the statistically significant factors for a poor outcome were age, the secondary character of the gangrene, the extent of the lesions, and association with diabetes mellitus and/or hypertension.

Conclusion

Fournier’s gangrene is still a frequent and lethal disease. Its good management requires a multidisciplinary approach.     

Les écosystèmes végétaux Pliocènes de catalogne méridionale. Variations latitudinales dans le domaine nord-ouest méditerranéen

enTwo sections have been analysed: San Onofrequarry and Pliocene deposits from Tarragona E2 hole which is biostratigraphically subdivided according to planktonic foraminifera. A latitudinal floristic differentiation is evidenced for South-Western European Lower Pliocene. The increasing open vegetation in the coastal plain is to be related to high xericity.     

Les possibilités de l'application des germes pathogènes dans la lutte contre les chenilles défoliatrices

Résumé L'utilisation des germes pathogènes est une solution du problème de la sélectivité. Des solutions concurrentes existent avec certains pesticides chimiques. L'utilisation des germes pathogènes est donc envisagée d'une manière pragmatique en négligeant les problèmes de recherches fondamentales. Pour cette raison les mycoses et les protozoonoses ne sont pas retenues. Les viroses offrent un exemple de la plus grande spécificité d'action. L'application des virus d'insectes a été surtout développée en sylviculture. Une grande difficulté est la multiplication des virus sur organismes vivants. Les bactérioses peuvent être seules retenues pour l'agriculture et l'arboriculture intensives: elles ont un spectre d'action assez étendu mais suffisamment sélectif; les bactéries qui nous intérresent peuvent être multipliées industriellement. Le statut deBacillus thuringiensis Berliner et les propriétés des préparations commerciales ont fait l'objet de développements récents. Dans une revue critique des applications de ces préparations en arboriculture fruitière, on considère d'abord le cas des Mineuses et des Tordeuses. Presque toutes ces chenilles sont susceptibles àB. thuringiensis. Mais la difficulté d'utilisation des préparations est de nature éthologique. De bons résultats sont obtenus au Canada contreArgyrotaenia et en U.R.S.S. contreHyponomcuta. En U.R.S.S. on utilise des produits mixtes à concentration réduite (0,5%) de préparation bactérienne et à concentration extrêmement faible (0,002%) de D.D.T. Les résultats contre le Carpocapse sont négatifs. Les résultats contre les chenilles défoliatrices sont très satisfaisants: en Hollande et au Canada contreMalacosoma; au Canada contre les Géométrides,Operophtera etAlsophila espèces très susceptibles àB. thuringiensis, à la dose de 1 à 2 pounds de préparation (titrant 30×10⁹ spores viables par gramme) pour 100 gallons, soit environ, 1,5%; en France, ces résultats sont confirmés. En conclusion, l'utilisation en verger des prépararations commerciales deBacillus thuringiensis doit être ?intégrée? dans un programme général de protection comprenant à la fois les traitements chimiques et les méthodes culturales. De tels programmes sont actuellement expérimentés dans certains vergers de Pommiers par l'I.P.O. et le T.N.O. en Hollande.     

Les feux préhistoriques holocènes en montagne sub-méditerranéenne : premiers résultats sur le Causse Méjean (Lozère,France)

Charcoal remains, evidence of ancient fire, have been discovered in the dolines of the asylvatic or deforested sub Mediterranean area, from the ‘Grands Causses’. First ¹⁴C AMS dating on Pinus cf. sylvestris charcoal, cover the period 4805–2990 yr BP. This testifies to the development of a pine forest in the transition Middle–Late Holocene. The existence of several phases of fires, affecting the forests in the northwestern areas of the Causse during the second part of the Holocene is also proved. The origin of present-day herbaceous vegetation seems to date back to the Bronze Age. To cite this article: D. Quilès et al., C. R. Palevol 1 (2002) 59–65.