Étude quantitative du parasitisme réalisé parTrichomalopsis peregrina dans les nids d'hiver d'Euproctis chrysorrhoea en chenaie

Les interactions h?te-parasito?de ont été abordées dans le cas du systèmeTrichomalopsis peregrina G. (Pteromalidae) et son h?te grégaireEuproctis chrysorrhoea L. (Lymantriidae), au cours de la phase diapausante des chenilles dans les nids d'hiver tissés par ce ravageur. Un échantillon de 1 432 nids d'hiver a été récolté dans 8 peuplements de chênes dans la région toulousaine durant l'hiver 1988. Le volume du nid a été utilisé comme estimateur du nombre de chenillesh?tes dans les nids et la réponse du parasito?de a été comparée à celle prévue par la théorie de la stratégie optimale de recherche. Les principaux résultats sont les suivants:

A divergent synthesis of [1-14C]-mono-E isomers of fatty acids

A convenient synthesis of [1-14C]-mono-trans fatty acid using olefin inversion as a key-step is described. This methodology allows for a facile synthesis of [1-14C]-labelled mono-trans analogues of oleic, linoleic and linolenic acids. As an example, only eleven steps were necessary to obtain the [1-14C]-mono-E isomers of linolenic acid from its commercial all-Z form. In the first step, Barton's decarboxylation procedure yielded a bromo intermediate. Epoxidation of this compound resulted in the formation of three monoepoxides, which could be separated by HPLC. After identification by 1H NMR and MS, the pure monoepoxides were then subjected to inversion consisting of a stereospecific deoxygenation followed by a beta-elimination step. Finally, the labelling was introduced by substitution of the bromine by a [14C]-cyano group followed by hydrolysis.     

Exploring the role of galectin 3 in kidney function: a genetic approach

Galectin 3 belongs to a family of glycoconjugate-binding proteinsthat participate in cellular homeostasis by modulating cellgrowth, adhesion, and signaling. We studied adult galectin 3null mutant (Gal 3–/–) and wild-type (WT) mice togain insights into the role of galectin 3 in the kidney. Byimmunofluorescence, galectin 3 was found in collecting duct(CD) principal and intercalated cells in some regions of thekidney, as well as in the thick ascending limbs at lower levels.Compared to WT mice, Gal 3–/– mice had ~11% fewerglomeruli (p < 0.04), associated with kidney hypertrophy(p < 0.006). In clearance experiments, urinary chloride excretionwas found to be higher in Gal 3–/– than in WT mice(p < 0.04), but there was no difference in urinary bicarbonateexcretion, in glomerular filtration, or urinary flow rates.Under chronic low sodium diet, Gal 3–/– mice hadlower extracellular fluid (ECF) volume than WT mice (p <0.05). Plasma aldosterone concentration was higher in Gal 3–/–than in WT mice (p < 0.04), which probably caused the observedincrease in -epithelial sodium channel (-ENaC) protein abundancein the mutant mice (p < 0.001). Chronic high sodium dietresulted paradoxically in lower blood pressure (p < 0.01)in Gal 3–/– than in WT. We conclude that Gal 3–/–mice have mild renal chloride loss, which causes chronic ECFvolume contraction and reduced blood pressure levels.     

Male secondary sexual structures and the systematics of the Thereus oppia species group (Lepidoptera,Lycaenidae, Eumaeini)

The Thereus oppia species group includes species with and without a scent pad, which is a histologically and morphologically characterized male secondary sexual structure on the dorsal surface of the forewing. To assess the hypothesis that these structures are lost evolutionarily, but not regained (Dollo’s Law), the taxonomy of this species group is revised. Thereus lomalarga sp. n., and Thereus brocki sp. n., are described. Diagnostic traits, especially male secondary structures, within the Thereus oppia species group are illustrated. Distributional and biological information is summarized for each species. Three species have been reared, and the caterpillars eat Loranthaceae. An inferred phylogeny is consistent with the hypothesis that scent pads in the Thereus oppia species group have been lost evolutionarily twice (in allopatry), and not re-gained.     

Extreme isolation by distance in a montane frog <Emphasis Type="Italic">Rana cascadae</Emphasis>

Given the recent interest in declining amphibian populations, it is surprising that there are so few data on genetic drift and gene flow in anuran species. We used seven microsatellite loci to investigate genetic structure and diversity at both large and small geographic scales, and to estimate gene flow in the Cascades frog, Rana cascadae. We sampled 18 sites in a hierarchical design (inter-population distances ranging from 1–670 km) to test for isolation by distance and to determine the geographic scale over which substantial gene flow occurs. Eleven of these sites were sampled as three fine-scale clusters of three, three, and five sites separated by pairwise distances of 1–23 km to estimate number of migrants exchanged per generation via F _ST and by a coalescent approach. We found R. cascadae exhibits a strong pattern of isolation by distance over the entire species range, and that there is a sharp drop in migrants exchanged between sites separated by greater than 10 km. These data, in conjunction with results of other recent studies, suggest that montane habitats promote unusually strong genetic isolation among frog populations. We discuss our results in light of future management and conservation of R. cascadae.     

ADAM19 autolysis is activated by LPS and promotes non-classical secretion of cysteine-rich protein 2

ADAM family proteins are type I transmembrane, zinc-dependent metalloproteases. This family has multiple conserved domains, including a signal peptide, a pro-domain, a metalloprotease domain, a disintegrin (DI) domain, a cysteine-rich (Cys) domain, an EGF-like domain, a transmembrane domain, and a cytoplasmic domain. The Cys and DI domains may play active roles in regulating proteolytic activity or substrate specificity. ADAM19 has an autolytic processing activity within its Cys domain, and the processing is necessary for its proteolytic activity. To identify a new physiological function of ADAM19, we screened for associating proteins by using the extracellular domain of ADAM19 in a yeast two-hybrid system. Cysteine-rich protein 2 (CRIP2) showed an association with ADAM19 through its DI and Cys domains. Sequence analysis revealed that CRIP2 is a secretable protein without a classical signal. CRIP2 secretion was increased by overexpression of ADAM19 and decreased by suppression of ADAM19 expression. Moreover, CRIP2 secretion increased in parallel with the autolytic processing of ADAM19 stimulated by lipopolysaccharide. These findings suggest that ADAM19 autolysis is activated by lipopolysaccharide and that ADAM19 promotes the secretion of CRIP2.     

A Cysteine Endopeptidase (“Dionain”) Is Involved in the Digestive Fluid of Dionaea muscipula (Venus’s Fly-trap)

The carnivorous plant Dionaea muscipula (Venus’s flytrap) secretes proteinases into the digestive fluid to digest prey proteins. In this study, we obtained evidence that the digestive fluid contains a cysteine endopeptidase, presumably belonging to the papain family, through inhibitor studies and partial amino acid sequencing of the major SDS–PAGE band protein. The name “dionain” is proposed for the enzyme.     

The Breivik case and what psychiatrists can learn from it

In the afternoon of July 22, 2011, Norwegian Anders Behring Breivik killed 77 persons, many of them children and youths, in two separate events. On August 24, 2012, he was sentenced to 21 years in prison. Breivik went through two forensic evaluations: the first concluded that he had a psychotic disorder, thus being legally unaccountable, whereas the second concluded that he had a personality disorder, thus being legally accountable. This article first describes Breivik's background and his crimes. This is followed by an overview of the two forensic evaluations, their methods, contents and disagreements, and how these issues were handled by the court in the verdict. Finally, the article focuses on some lessons psychiatrists can take from the case.     

Inhibitors of sphingolipid metabolism enzymes

Sphingolipids are a family of lipids that play essential roles both as structural cell membrane components and in cell signalling. The cellular contents of the various sphingolipid species are controlled by enzymes involved in their metabolic pathways. In this context, the discovery of small chemical entities able to modify these enzyme activities in a potent and selective way should offer new pharmacological tools and therapeutic agents.