Genetic background of osteoporosis.

Osteoporosis is a systemic disorder of decreased skeletal mass as measured by bone mineral density (BMD), and disturbed skeletal architecture and function which results in an increased risk for bone fractures with consecutively increased morbidity and mortality. Twin and family studies have shown an important genetic component of BMD of about 40-60%. This exceeds other well known factors influencing BMD such as environmental factors like dietary calcium, physical activity or several drugs and diseases. Therefore, interest increased in the genetic background of bone mineral density. Polymorphisms of the Vitamin D receptor gene were the first to be published in this area. Studies on other loci or candidate genes such as the estrogen receptor gene or the collagen type I alpha1 gene also showed associations with bone mineral density that could explain at least a part of the genetic background of osteoporosis. Recently published data suggest that these genetic markers of bone metabolism are important in interaction with each other or in certain bone-affecting diseases. In the future, genetic studies on osteoporosis will have to screen further relevant genes and markers for bone metabolism as well as to evaluate the complex interactions of genetic influences, so that it would be possible to calculate a patient's individual risk for osteoporosis in the context of environmental influences.

Application of response surface methodology to evaluation of bioconversion experimental conditions.

Using Candida tenuis, a yeast isolated from the digestive tube of the larva of Phoracantha semipunctata (Cerambycidae, Coleoptera), we were able to demonstrate the bioconversion of citronellal to citronellol. Response surface methodology was used to achieve the optimization of the experimental conditions for that bioconversion process. To study the proposed second-order polynomial model, we used a central composite experimental design with multiple linear regression to estimate the model coefficients of the five selected factors believed to influence the bioconversion process. Only four were demonstrated to be predominant: the incubation pH, temperature, time, and the amount of substrate. The best reduction yields (close to 90%) were obtained with alkaline pH conditions (pH 7.5), a low temperature (25 degrees C), a small amount of substrate (15 mul), and short incubation time (16 h). This methodology was very efficient: only 36 experiments were necessary to assess these conditions, and model adequacy was very satisfactory as the coefficient of determination was 0.9411.

Preference of certain scolytidae for different conifers : A statistical approach.

Nine Scolytidae (Cryphalus piceae, Cryphalus abietis, Pityokteines curvidens, Dendroctonus micans, Ips sexdentatus, Ips typographus,Orthotomicus erosus, Tomicus piniperda, andPhloeosinus bicolor) were subjected to olfaction tests on ten conifer species taken two by two. These conifers wereAbies cephalonica, Abies nordmanniana, Picea abies, Picea orientalis, Pinus pinaster, Pinus sylvestris, Pinus brutia, Pinus laricio,Cupressus atlantica, andCupressus sempervirens. A statistical study of the results, by means of the factorial analysis of correspondence completed by the duo preference test, commonly used in sensory analysis, revealed a taxonomic clustering by genus of the plant species and analogous specific attraction behavior for the insects.Pityokteines curvidens has a behavior analogous to that of the twoCryphalus considered.Phloesinus bicolor shows a very strong specificity forCupressus. The essential oils of the conifers were analyzed to determine their terpene composition and the ten odor spectra thus obtained were compared. The hierarchical classification, using a Euclidian distance, brought out similarities in the spectra, especially in the case ofPinus. It is shown that definitive establishment of Scolytidae is not due to the presence in the odor spectrum of any particular terpenoid. The attractive power of a species results from the synergism of the different terpenes. Moreover the definitive establishment of the insects also depends on their sensorial adaptation to volatile substances which can be wider or narrower for the species studied.

[Comparative study of the glycosidases of 2 Lepidoptera wood-eating Cossidae (Cossus cossus L., and Zeuzera pyrina L.) and various wood-eating Coleoptera]. / Etude comparée de de l'éqipement osidasique de 2 Lépidoptères Cossidae xylophages (Cossus cossus L. et Zeuzera pyrina L.) et de divers Coléoptères xylophages.

The authors present here the results of their research concerning the study of the osidases of the caterpillars Cossus cossus L. and Zeuzera pyrina L. (Lepidoptera Cossidae). Its enzyme equipment shows very important differences compared to the different species of Scolytidae, Cerambycidae, Curculionidae and Buprestidae. The differences are lie especially in the absence of some osidases acting on polysaccharides (hémicelluloses and cellulose).

[Specificity of the response of monogamous and polygamous Scolytidae to the attraction exerted by digestive residues (feces)]. / Spécificité de la réponse des Scolytidae monogrames et polygames à l'attraction exercée par les résidus de la digestion (déjections)

This paper will emphasize studies of sex attractant in the polygamus species of Scolytidae genus (Phloeosinus, Pityogenes, Pityophthorus) and monogamus species genus Cryphalus, Blastophagus. The secondary attractant or "sex pheromone" was localized in the frass material produced by male beetle in polygamus bark beetles and by female in monogamus species; pheromone specificity has been studied in differents species Phloeosinus, Pityogenes, Pityophthorus, etc. This specificity was evaluated by exposing groups of female beetles to comparable quantities of frass from male polygamus bark beetles.