Variability over time and correlates of cholesterol and blood pressure in systemic lupus erythematosus: a longitudinal cohort study

Introduction  

Total cholesterol (TC) and blood pressure (BP) are likely to take a dynamic course over time in patients with systemic lupus erythematosus (SLE). This would have important implications in terms of using single-point-in-time measurements of these variables to assess coronary artery disease (CAD) risk. The objective of this study was to describe and quantify variability over time of TC and BP among patients with SLE and to determine their correlates.     

Desensitization of the δ-Opioid Receptor Correlates with Its Phosphorylation in SK-N-BE Cells: Involvement of a G Protein-Coupled Receptor Kinase

Abstract: Phosphorylation of G protein-coupled receptors is considered an important step during their desensitization. In SK-N-BE cells, recently presented as a pertinent model for the studies of the human δ-opioid receptor, pretreatment with the opioid agonist etorphine increased time-dependently the rate of phosphorylation of a 51-kDa membrane protein. Immunological characterization of this protein with an antibody, raised against the amino-terminal region of the cloned human δ-opioid receptor, revealed that it corresponded to the δ-opioid receptor. During prolonged treatment with etorphine, phosphorylation increased as early as 15 min to reach a maximum within 1 h. Phosphorylation and desensitization of adenylyl cyclase inhibition paralleled closely and okadaic acid inhibited the resensitization, a result strongly suggesting that phosphorylation of the δ-opioid receptor plays a prominent role in its rapid desensitization. The increase in phosphorylation of the δ-opioid receptor, as well as its desensitization, was not affected by H7, an inhibitor of protein kinase A and protein kinase C, but was drastically reduced by heparin or Zn²⁺, known to act as G protein-coupled receptor kinase (GRK) inhibitors. These results are the first to show, on endogenously expressed human δ-opioid receptor, that a close link exists between receptor phosphorylation and agonist-promoted desensitization and that desensitization involves a GRK.     

A New Electrolyte Formulation for Securing High Temperature Cycling and Storage Performances of Na‐Ion Batteries

The Na‐ion battery is recognized as a possible alternative to the Li‐ion battery for applications where power and cost override energy density performance. However, the increasing instability of their electrolyte with temperature is still problematic. Thus, a central question remains how to design Na‐based electrolytes. Here, the discovery of a Na‐based electrolyte formulation is reported which enlists four additives (vinylene carbonate, succinonitrile, 1,3‐propane sultone, and sodium difluoro(oxalate)borate) in proper quantities that synergistically combine their positive attributes to enable a stable solid electrolyte interphase at both negative and positive electrodes surface at 55 °C. Moreover, the role of each additive that consists in producing specific NaF coatings, thin elastomers, sulfate‐based deposits, and so on via combined impedance and X‐ray photoelectron spectroscopy is rationalized. It is demonstrated that empirical electrolyte design rules previously established for Li‐ion technology together with theoretical guidance is vital in the quest for better Na‐based electrolytes that can be extended to other chemistries. Overall, this finding, which is implemented to 18 650 cells, widens the route to the rapid development of the Na‐ion technology based on Na₃V₂(PO₄)₂F₃/C chemistry.     

Characterization of messenger RNA from epimastigotes and metacyclic trypomastigotes of Trypanosoma cruzi

The cell-free translation products of polyribosomal and post-polyribosomal mRNAs from the non-infective epimastigotes and the infective metacyclic trypomastigotes of the parasitic protozoan Trypanosoma cruzi were compared by two-dimensional polyacrylamide gel electrophoresis. The result show that although many polypeptides are conserved, quantitative and qualitative differences are observed between both differentiation stages. The results also indicate the existence of post-polyribosomal mRNAs in equilibrium with polyribosomal counterparts. The immunoprecipitation of the in vitro synthesized polypeptides with chagasic human serum and the serum raised against an 85-kDa glycoprotein (P2-WGA), potentially involved in the process of T. cruzi penetration into mammalian cells, shows that while the chagasic serum recognizes the same 72-kDa, 68-kDa and 46-kDa polypeptides in both differentiation stages, the anti-P2-WGA serum immunoprecipitates a single 48-kDa polypeptide from in vitro translation products of metacyclic trypomastigotes.     

Can transposable element copy number distribution parameters be estimated from natural populations of Drosophila melanogaster?

The copy frequency distribution of a transposable element family in a Drosophila melanogaster natural population is generally characterised by the values of the Charlesworths' model parameters α and β (Charlesworth & Charlesworth, 1983). The estimation of these parameters is made using the observed distribution of the occupied sites in a population sample. Several results have been interpreted as due either to the influence of stochastic factors or to deterministic factors (transposition, excision, selection…). The accuracy of this method was tested by estimations performed on samples from simulated populations. The results show that with the sample size usually used for natural population studies, the confidence intervals are too large to reasonably deduce either the element copy number distribution or the values of transposition and excision rate and selective coefficients.     

Electrophoretic analysis of endonuclease-generated fragments of k-DNA, of esterase isoenzymes, and of surface proteins as aids for species identification of insect trypanosomatids

In order to verify the applicability of biochemical methods for species identification of Trypanosomatidae, 13 species of monoxenic trypanosomatids plus the heteroxenous Trypanosoma cruzi were comparatively analyzed by three different biochemical methods. Insect trypanosomatids examined were: Crithidia acanthocephali, C. fasciculata (three varieties), C. luciliae luciliae, C. luciliae thermophila, C. deanei, C. oncopelti, Herpetomonas muscarum muscarum, H. megaseliae, H. samuelpessoai, H. mariadeanei, Leptomonas seymouri, L. collosoma, L. samueli, and Blastocrithidia culicis. Also included in the survey were aposymbiotic strains of C. deanei and C. oncopelti. Methods used were: electrophoretic profiling of endonuclease-generated fragments of k-DNA, esterase isoenzymes profiling, and polyacrylamide-gel electrophoresis (SDS-PAGE) of radioiodinated cell surface proteins. Interspecific but not intraspecific differences were detected by all three methods among the 13 monoxenic species examined. Thus, it is concluded that these methods can be successfully used, in addition to classical criteria, for species identification of insect trypanosomatids.     

Ethylene effects on growing and gravireacting maize root segments

The effects of ethylene pretreatments (500 nl/l for 1 h) and treatments (100 nl/1 to 1000 nl/l for 6 h) on elongation and gravireaction of apical maize root segments were tested in light and in the dark. Ethylene was found to affect weakly root elongation and gravireaction, but to induce strong curvatures for root growing vertically.     

Ammonium photo-production by heterocytous cyanobacteria: potentials and constraints

Over the last decades, production of microalgae and cyanobacteria has been developed for several applications, including novel foods, cosmetic ingredients and more recently biofuel. The sustainability of these promising developments can be hindered by some constraints, such as water and nutrient footprints. This review surveys data on N₂-fixing cyanobacteria for biomass production and ways to induce and improve the excretion of ammonium within cultures under aerobic conditions. The nitrogenase complex is oxygen sensitive. Nevertheless, nitrogen fixation occurs under oxic conditions due to cyanobacteria-specific characteristics. For instance, in some cyanobacteria, the vegetative cell differentiation in heterocyts provides a well-adapted anaerobic microenvironment for nitrogenase protection. Therefore, cell cultures of oxygenic cyanobacteria have been grown in laboratory and pilot photobioreactors (Dasgupta et al., 2010; Fontes et al., 1987; Moreno et al., 2003; Nayak & Das, 2013). Biomass production under diazotrophic conditions has been shown to be controlled by environmental factors such as light intensity, temperature, aeration rate, and inorganic carbon concentration, also, more specifically, by the concentration of dissolved oxygen in the culture medium. Currently, there is little information regarding the production of extracellular ammonium by heterocytous cyanobacteria. This review compares the available data on maximum ammonium concentrations and analyses the specific rate production in cultures grown as free or immobilized filamentous cyanobacteria. Extracellular production of ammonium could be coupled, as suggested by recent research on non-diazotrophic cyanobacteria, to that of other high value metabolites. There is little information available regarding the possibility for using diazotrophic cyanobacteria as cellular factories may be in regard of the constraints due to nitrogen fixation.