High-performance liquid chromatography of ecdysone metabolites applied to the cabbage butterfly, Pieris brassicae L

HPLC allowed separation of twelve major labeled compounds after injection of ³H-ecdysone into Pieris pharate pupae. These compounds were identified as six pairs of metabolites (3α and 3β epimers), comprising ecdysone, 20-hydroxyecdysone, 26-hydroxyecdysone, 20,26-dihydroxy-ecdysone and the polar metabolites P and 20-hydroxy-P. These last two products could not be enzymatically split by any hydrolase tested and are weak acids arising respectively from 26-hydroxyecdysone and 20,26-dihydroxyecdysone. They might be 26-oic compounds.Epimerization appears as a fundamental inactivation process in Pieris and could well be a general characteristic of closed systems (eggs and pupae). No significant amounts of hydrolyzable conjugates were detected in our biological system (pharate pupae and pupae).     

Assessing the contributions of multiple interacting traits to plant reproductive success: environmental dependence

The reproductive success of sibling cocklebur plants (Compositae: Xanthium strumarium) was monitored after growth at different levels of availability of water and nutrient resources. Variation in reproductive success among individual plants was related to physiological, structural, and phenological characteristics. Reproductive success increased with increased availability of resources, but the relative contribution of particular traits to reproductive success varied with resource availability. Allocation of biomass to different vegetative tissues, time to seedling emergence, degree of branching, transpiration rates, water use efficiency, the rate of decline in height growth after seedling emergence and final plant size all varied significantly with resource availability. However, the changes in each of these phenotypic traits across three garden environments did not always correlate with reproductive success. The shifts across environments in the apparent importance of somatic traits for reproductive success were attributed to plastic changes in the traits but also to changes in the phenotypic correlations of the traits with reproductive success.     

Synthesis and nuclear magnetic resonance study of 3-dehydroecdysteroids

Several 3-dehydro- (or 3-oxo-) ecdysteroids have been prepared by enzymatic and/or chemical means. Methods for their purification using various high-performance liquid chromatography systems are described. Proton and carbon nuclear magnetic resonance analyses show that 3-dehydroecdysteroids when dissolved in water or methanol (but not in chloroform) present a temperature-dependent equilibrium between two forms. The possible structure of these two forms is discussed.     

Le rôle de l’église et de la morale chrétienne sur le contrôle des naissances dès l’Antiquité à nos jours

This article discusses the role of the Church in birth control from Antiquity to the present day.     

Impact of Superoxide Dismutase Mimetic AEOL 10150 on the Endothelin System of Fischer 344 Rats

Endothelin-1 is a potent vasoconstrictor and mitogenic peptide involved in the regulation of vasomotor tone and maintenance of blood pressure. Oxidative stress activates the endothelin system, and is implicated in pulmonary and cardiovascular diseases including hypertension, congestive heart failure, and atherosclerosis. Superoxide dismutase mimetics designed with the aim of treating diseases that involve reactive oxygen species in their pathophysiology may exert a hypotensive effect, but effects on the endothelin system are unknown. Our objective was to determine the effect of the superoxide dismutase mimetic AEOL 10150 on the basal endothelin system in vivo. Male Fischer-344 rats were injected subcutaneously with 0, 2 or 5 mg/kg body weight of AEOL 10150 in saline. Plasma oxidative stress markers and endothelins (bigET-1, ET-1, ET-2, ET-3) as well as lung and heart endothelin/nitric oxide system gene expressions were measured using HPLC-Coularray, HPLC-Fluorescence and RT-PCR respectively. AEOL 10150 reduced (p<0.05) the circulating levels of isoprostane (-25%) and 3-nitrotyrosine (-50%) measured in plasma 2h and 24h after treatment, confirming delivery of a physiologically-relevant dose and the potent antioxidant activity of the drug. The reduction in markers of oxidative stress coincided with sustained 24h decrease (p<0.05) of plasma levels of ET-1 (-50%) and ET-3 (-10%). Expression of preproET-1 and endothelin converting enzyme-1 mRNA were not altered significantly in the lungs. However preproET-1 (not significant) and ECE-1 mRNA (p<0.05) were increased (10–25%) in the heart. Changes in the lungs included decrease (p<0.05) of mRNA for the ET-1 clearance receptor ET_B and the vasoconstriction-signaling ET_A receptor (-30%), and an early surge of inducible nitric oxide synthase expression followed by sustained decrease (-40% after 24 hours). The results indicate that interception of the endogenous physiological flux of reactive nitrogen species and reactive oxygen species in rats impacts the endothelin/nitric oxide system, supporting a homeostatic relationship between those systems.     

Trace metal requirements in total parenteral nutrition (TPN). 5. Formation constants for the copper(II)--histidine ternary complexes with threonine, lysine, glycine, phenylalanine, valine, and cystine, and discussion of their implications regarding the copper distribution in blood plasma during TPN and the evaluation of the daily dose of copper

Specific metal deficiencies have been reported to affect patients receiving total parenteral nutrition (TPN). Our previous studies on the topic were devoted to the computer-based interpretation of the extra urinary excretion of zinc; a theoretical approach was also proposed, with a view to compensating for the extra losses of this metal. Similarly, the present work deals with the problem of TPN-induced copper deficiency and its remedy. As is the case for zinc, the TPN-induced excretion of copper clearly stems from the relative mobilization of the plasma protein-bound pool of this metal into its diffusable low-molecular-weight fraction; this phenomenon being due to the competitive complexation of copper by the amino acids of the nutritive solution. The computer simulation of this effect thus required that first the equilibrium constants be experimentally determined for the main complexes of copper that might form in the solution as well as in plasma during the infusion. Accordingly, complex formation in the copper-histidine ternary systems with threonine, lysine, glycine, phenylalanine, valine, and cystine was investigated by potentiometry at 37 degrees C in NaCIO4 0.15 mol X dm-3. The implications of the results obtained are discussed with regard to the interpretation of the copper excretion and the estimation of the desirable daily dose of this metal for the TPN mixture under consideration.