Prise en charge des complications de la maladie d’Alzheimer: mise au point

Complications in Alzheimer’s disease such as functional decline, weight loss, gait and balance disturbances and behavioral and psychological symptoms in dementia (BPSD) have a negative impact on quality of life. It is therefore important to identify these complications at an early stage. BPSD are major features of Alzheimer’s disease and related disorders. They represent half of admissions to special care units with, in order of frequency, agitation and agressivity. The non pharmacological approach must be implemented first and linked to a pharmacological approach. Weight loss is of complex physiopathology. It can be monitored by observation of the weight curve and use of the Mini Nutritional Assessment (MNA). Weight loss may be responsible for an increased risk of institutionalization and mortality. Gait and balance disturbances are also a prevalent complication of the illness and lead to an increased risk of falls and injuries. Neurological complications take the form of seizures and motor symptoms. Amongst these complications the burden of the caregiver must also be assessed. These complications and their consequences must be identified and, wherever possible, prevented with a specific care plan.     

Remarques sur le métabolisme de l'acide acétique chez la levure au cours de la sporulation

We have noticed important metabolic modifications during the first 15 hours of the sporulation process of yeast in contact with acetic acid. Carbohydrate reserves, dry weight and proteins increase. On the other hand, the activity of fumarase and isocitritase in cell homogenates are hardly altered. The results prove true the hypothesis according to which the metabolism of acetic acid is altered during sporulation.

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Zusammenfassung Beträchtliche metabolische Veränderungen wurden bei Hefe, während der fünfzehn ersten Stunden der Sporenbildung unter Zugabe von Essigsäure, beobachtet. Der Kohlenhydratenvorrat, die Trockensubstanz und der Proteingehalt nehmen zu. Die Aktivität der Fumarase und Isocitritase wird kaum verändert. Dadurch wird die Annahme bestätigt, daß eine Abweichung des Metabolismus der Essigsäure während der Sporenbildung stattfindet.

     

Mise au point d'un milieu nutritif pour la culture profonde du champignon entomopathogèneNomuraea rileyi

Résumé La blastogenèse deNomuraea rileyi (Farlow) Samson requiert des besoins très spécifiques. La présence de Tween et une forte concentration en extrait de levure sont indispensables. Contrairement aux conidies, les blastospores obtenues ne sont pas capables de traverser le tégument de l'h?te alors qu'il est démontré que les blastospores de quelques autres espèces sont effectivement entomopathogènes par la voie tégumentaire.

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Summary Nomuraea rileyi (Farlow) Samson blastogenesis requires very specific factors which may change according to the biotype. Limiting components of the medium can be the presence of Tween 80 and a high concentration of yeast extract. The blastospores obtained are not infective when applied topically.

     

Une étude complémentaire sur la physico-chimie de la sexualité

Sans résumé     

Influence de la température d'élevage sur la fertilité des pontes de Schistocerca gregaria

Thermal conditions, within the range of ambient temperature that permits normal development, colour changes, and the behaviour characterizing sexual maturity of Schistocerca, may influence the fertility of pods estimated as the percentage of viable eggs yielding hoppers. When the insects are kept at 20°C during the night, and from 33 to 42°C during the day, the percentage of hatching is normal and rather constant during the whole parental life. When the diurnal temperature is 30°C, the rate of hatching decreases steadily as the adults grow older. At 28°C, all the pods are sterile from the beginning of the reproductive period.Interbreeding of adults reared at different diurnal temperatures shows that the males are mainly responsible for the sterility of the pods laid at 28°C; under these conditions, copulation occurs but there is no fertilization. Perturbations arising from this low temperature persist since the males do not recover their ability to fertilize females when transferred to a warmer environment.Females too are responsive to thermal conditions, but the functional disturbances provoked by a low temperature are not as serious as in the case of males and they do not last so long. A number of females bred at 28°C can be fertilized. When fertilization does occur, the percentage of hatching depends on the temperature existing at the time of laying and, especially, on the previous thermal conditions. When there is no fertilization, parthenogenetic reproduction can occur with a frequency that increases with a rise in external temperature from 28 to 36°C.     

Considérations sur la distribution structurale d'un peuplement de pin sylvestre d'un marais oligotrophe (Roumanie)

Summary In the present paper the authors are undertaking to show the correlation that exists, between the age, density of the trees and the coefficient of aggregation of a population of pines studied in the Lucs bogs-reservation of the Harghita Mountains (Rumania). The pines which have been studied are relics and a number of arctic elements (Sparganium minimum, Potamogeton alpinus, Betula nana) had survived with them. A geobotanical survey showed that the micro-distribution of the pine population presents, in spite of the uniformity of the ecological and phytosociological conditions, fluctuations of density as well as of aggregation which thus reflect the existence of some intense phytosociological processes in the apparently stationary structure of the trees. The coefficient of aggregation of the population under study has been determined by the Hopkins-method, based on some linear measurements carried out between the points determined at random (by chance) and the nearest vegetal individuals as well as between pairs of individuals chosen at random.The measurements have established that the structure of the trees which presented initially an aggregated dispersion, evolve together a natural elaquating towards the achievement of a normal dispersion. The calculation of the entropy of spatial distribution based on a determination of the probability of frequency of each of the calculated distances shows a significant growth of the entropy of spatial distribution of the constituent elements; this shows that the spatial structure of the population analysed evolves towards the stage of the highest probability, this being identical with the condition of statistical stability in which, however, the evolution of phytosociological processes continued.     

Nutrition et élevage du prédateur polyphageMacrolophus caliginosus [Heteroptera,Miridae] sur milieux artificiels

La possibilité de nourrir la punaiseMacrolophus caliginosus Wagner à l'aide de milieux artificiels a été testée. En l'absence de végétal, les témoins nourris avec des ?ufs d'Ephestia kuehniella Zeller ont une survie médiocre et fournisent 33% d'adultes. Avec le meilleur milieu artificiel la survie est comparable à celle des témoins et 21 % d'adultes sont obtenus. Avec ce même milieu, mais en présence de feuille de géranium, la production d'adultes atteint 62%. Les compositions en acides aminés des punaises élevées avec le milieu montrent des écarts inférieurs à 20% par rapport aux témoins. Le développement complet deM. caliginosus nourri à l'aide de milieu artificiel a été obtenu. Le végétal joue un rôle important dans la biologie de ce prédateur.