Functional evidence of distinct electrophile-induced activation states of the ion channel TRPA1

Transient Receptor Potential Ankyrin 1 (TRPA1) is a tetrameric, nonselective cation channel expressed on nociceptive sensory nerves whose activation elicits nocifensive responses (e.g. pain). TRPA1 is activated by electrophiles found in foods and pollution, or produced during inflammation and oxidative stress, via covalent modification of reactive cysteines, but the mechanism underlying electrophilic activation of TRPA1 is poorly understood. Here we studied TRPA1 activation by the irreversible electrophiles iodoacetamide and N-ethylmaleimide (NEM) following transient expression in HEK293 cells. We found that in Ca²⁺ imaging studies C621 is critical for electrophile-induced TRPA1 activation, but the role of C665 in TRPA1 activation is dependent on the size of the electrophile. We identified slower TRPA1 activation in whole-cell recordings compared to studies with intact cells, which is rescued by pipette solution supplementation with the antioxidant glutathione. Single-channel recordings identified two distinct electrophilic-induced TRPA1 activation phases: a partial activation that, in some channels, switched to full activation with continued electrophile exposure. Full activation but not the initial activation was regulated by C665. Fitting of open time distributions suggests that full activation correlated with an additional (and long) exponential component, thus suggesting the phases are manifestations of distinct activation states. Our results suggest that distinct NEM-induced TRPA1 activation states are evoked by sequential modification of C621 then C665.     

Occurrence of Nontuberculous Mycobacterial Pulmonary Infection in an Endemic Area of Tuberculosis

The majority of investigations of the epidemiology of nontuberculous mycobacteria (NTM) have focused on highly developed nations with a low prevalence of tuberculosis. In contrast, the Para state of north Brazil represents an area of high tuberculosis prevalence and increasing NTM incidence. Toward the goal of understanding the dynamics of infection by all Mycobacterium species, we report patient characteristics and the identification of NTM strains isolated from sputum samples from patients that were residents of Para, a state in the Amazon region, Northern of Brazil, over the period January 2010 through December 2011 (2 years). The 29 NTM patients comprised 13.5% of positive mycobacterial cultures over the 2-year period. A major risk factor for NTM pulmonary disease was previous tuberculosis (76%). Further, the average age of NTM patients (52 years) was significantly higher than that of tuberculosis patients (39 years) and more were female (72.4% vs. 37.4%). Unlike other Brazilian states, NTM pulmonary patients in Para were infected with a different spectrum of mycobacteria; primarily the rapidly growing Mycobacterium massiliense and Mycobacterium simiae complex.     

Intérêt de l’imagerie hybride TEMP/TDM dans la localisation des glandes parathyroïdes ectopiques : à propos de 3 cas

The presence of a parathyroid gland in ectopic position constitutes one of the leading causes of surgery failure. For this purpose, scintigraphy takes a major place in the anatomical localization of pathological parathyroid and so facilitates its treatment. The advent of hybrid cameras combining single photon emission tomography to CT (SPECT/CT) has further strengthened the contribution of this imaging modality in the precise localization of ectopic parathyroid and its anatomical relationships. The objective of our work is to illustrate the interest of hybrid imaging SPECT/CT, compared to planar scintigraphy and ultrasounds within the framework of primary hyperparathyroidism, particularly ectopic situation through three cases.     

Preparation of N2, N2,7-trimethylguanosine affinity columns

2,2,7-trimethylguanosine (TMG) binding proteins from human cells were purified through TMG-affinity columns. TMG synthesis was improved and the TMG obtained was shown to be similar to the TMG in the 5' cap of the UsnRNAs. The eluates obtained with TMG-affinity chromatographies were very different from those isolated with m7G-affinity columns, thus suggesting that specific TMG-binding proteins were obtained. The fraction may be enriched with factors associated with import and/or hypermethylation of UsnRNPs.     

A new class of potent non-imidazole H(3) antagonists: 2-aminoethylbenzofurans

2-aminoethylbenzofurans constitute a new class of H(3) antagonists that are more rotationally constrained than most previously reported H(3) antagonists. They retain high potency at human and rat receptors, with efficient CNS penetration observed in 35. The SAR of the basic amine moiety was compared in three different series of analogues. The greatest potency was found in analogues bearing a 2-methylpyrrolidine, a 2,5-dimethylpyrrolidine, or a 2,6-dimethylpiperidine.     

Three-phase partitioning as an efficient method for extraction/concentration of immunoreactive excreted-secreted proteins of Corynebacterium pseudotuberculosis

The three-phase partitioning (TPP) technique was used upstream to isolate/concentrate secreted proteins from Corynebacterium pseudotuberculosis cultured in a complex liquid medium. Several parameters of the TPP technique (15, 30, or 60% ammonium sulfate concentration; 4.0, 5.5, or 7.0 pH; and primary (n) or tertiary (t)-butanol solvent isomer) were varied to determine the optimal recovery of serologically and cellularly immunoreactive extracted proteins. A TPP extraction made with 30% ammonium sulfate and an initial pH of 4.0 gave the best humoral and cellular immunoreactivity of caseous lymphadenitis infected goats. In particular, two immunogenic secreted (16 and 125 kDa) proteins, which had not been found by other extraction methods, were identified.     

Comparative genomic mapping between a 754 kb region flanking DREB1A in Arabidopsis thaliana and maize

Comparative mapping between model plant species for which the complete genome sequence is known and crop species has been suggested as a new strategy for the isolation of agronomically valuable genes. In this study, we tested whether comparative mapping between Arabidopsisand maize of a small region (754 kb) surrounding the DREB1A gene in Arabidopsis could lead to the identification of an orthologous region in maize containing the DREB1A homologue. The genomic sequence information available for Arabidopsis allowed for the selection of conserved, low-copy genes that were used for the identification of maize homologues in a large EST database. In total, 17 maize homologues were mapped. A second BLAST comparison of these genes to the recently completed Arabidopsis sequence revealed that 15 homologues are likely to be orthologous as the highest similarity score was obtained either with the original Arabidopsis gene or with a highly similar Arabidopsis gene localized on a duplication of the investigated region on chromosome 5. The map position of these genes showed a significant degree of orthology with the Arabidopsis region. Nevertheless, extensive duplications and rearrangements in the Arabidopsisand maize genomes as well as the evolutionary distance between Arabidopsis and maize make it unlikely that orthology and collinearity between these two species are sufficient to aid gene prediction and cloning in maize.     

Synthesis and SAR of aminoalkoxy-biaryl-4-carboxamides: novel and selective histamine H3 receptor antagonists

Novel 4'-[(NR1R2-1-yl)]-propoxy-biaryl-4-carboxamides were designed and synthesized. All compounds were tested for affinity at histamine H(3)receptors. Most compounds were highly potent and selective for human and rat H(3) receptors and selected examples such as A-349821 showed functional antagonism of H(3) receptors in vitro and in a mouse dipsogenia model.     

4-[6-(2-Aminoethyl)naphthalen-2-yl]benzonitriles are potent histamine H3 receptor antagonists with high CNS penetration

4-[6-(2-Tertiaryaminoethyl)naphthalen-2-yl]benzonitriles are conformationally constrained histamine H3 receptor antagonists with high potency and selectivity. The analogs were designed around a naphthalene core, with the goal of enhancing lipophilicity and CNS penetration, as compared to a previously reported benzofuran series. The SAR of the tertiary amine moiety is similar to that reported for the benzofuran series, with analogs bearing a 2-methylpyrrolidine substituent possessing the greatest rat and human H3 receptor binding affinities.     

An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.