Long-lasting and controlled antioxidant property of immobilized gold nanoparticles for intelligent packaging.

The development of new packaging able to preserve sensitive biomolecules against oxidative stress is an important field. Several studies refer to antioxidant properties carried out by colloidal gold nanoparticles (AuNP). Herein, the purpose was to check whether this property is preserved when AuNP are immobilized on a glass support. After nanostructured film preparation, the physicochemical characterization proved that AuNP were well-individualized in the films with a high density of immobilization. Two radicals: ABTS•+ and DPPH• were used to investigate their antioxidant capacity. The results showed that immobilized AuNP had a preserved antioxidant capacity characterized by a different kinetic: more controlled and more prolonged but with the same efficiency (vs the same quantity of colloidal AuNP). The AuNP films demonstrated a capacity to prevent from degradation a molecule containing a thiol function. A 10-fold increase of N-acetylcysteine half-life was measured using the immobilized AuNP, highlighting the interest of the developed and adaptable support.

Novel genes and insights in complete asthma remission: A genome-wide association study on clinical and complete asthma remission.

BACKGROUND: Asthma is a chronic respiratory disease without a cure, although there exists spontaneous remission. Genome-wide association (GWA) studies have pinpointed genes associated with asthma development, but did not investigate asthma remission. OBJECTIVE: We performed a GWA study to develop insights in asthma remission. METHODS: Clinical remission (ClinR) was defined by the absence of asthma treatment and wheezing in the last year and asthma attacks in the last 3 years and complete remission (ComR) similarly but additionally with normal lung function and absence of bronchial hyperresponsiveness (BHR). A GWA study on both ClinR and ComR was performed in 790 asthmatics with initial doctor diagnosis of asthma and BHR and long-term follow-up. We assessed replication of the 25 top single nucleotide polymorphisms (SNPs) in 2 independent cohorts (total n = 456), followed by expression quantitative loci (eQTL) analyses of the 4 replicated SNPs in lung tissue and epithelium. RESULTS: Of the 790 asthmatics, 178 (23%) had ClinR and 55 ComR (7%) after median follow-up of 15.5 (range 3.3-47.8) years. In ClinR, 1 of the 25 SNPs, rs2740102, replicated in a meta-analysis of the replication cohorts, which was an eQTL for POLI in lung tissue. In ComR, 3 SNPs replicated in a meta-analysis of the replication cohorts. The top-hit, rs6581895, almost reached genome-wide significance (P-value 4.68 × 10-7 ) and was an eQTL for FRS2 and CCT in lung tissue. Rs1420101 was a cis-eQTL in lung tissue for IL1RL1 and IL18R1 and a trans-eQTL for IL13. CONCLUSIONS AND CLINICAL RELEVANCE: By defining a strict remission phenotype, we identified 3 SNPs to be associated with complete asthma remission, where 2 SNPs have plausible biological relevance in FRS2, CCT, IL1RL1, IL18R1 and IL13.

The asthma-rhinitis multimorbidity is associated with IgE polysensitization in adolescents and adults.

BACKGROUND: Children with multimorbid asthma and rhinitis show IgE polysensitization to several allergen sources. This association remains poorly studied in adolescents and adults using defined allergen molecules. We investigated IgE sensitization patterns towards a broad panel of aeroallergen components in adults and adolescents with a focus on individuals with asthma and rhinitis multimorbidity. METHODS: IgE reactivity to 64 micro-arrayed aeroallergen molecules was determined with the MeDALL-chip in samples from the French EGEA study (n = 840, age = 40.7 ± 17.1) and the Swedish population-based birth cohort BAMSE (n = 786, age = 16 ± 0.26). The age- and sex-adjusted associations between the number of IgE-reactive allergen molecules (≥0.3 ISU) and the asthma-rhinitis phenotypes were assessed using a negative binomial model. RESULTS: Groups representing 4 phenotypes were identified: no asthma-no rhinitis (A-R-; 30% in EGEA and 54% in BAMSE), asthma alone (A+R-; 11% and 8%), rhinitis alone (A-R+; 15% and 24%) and asthma-rhinitis (A+R+; 44% and 14%). The numbers of IgE-reactive aeroallergen molecules significantly differed between phenotypes (median in A-R-, A+R-, A-R+ and A+R+: 0, 1, 2 and 7 in EGEA and 0, 0, 3 and 5 in BAMSE). As compared to A-R- subjects, the adjusted ratio of the mean number of IgE-reactive molecules was higher in A+R+ than in A+R- or A-R+ (10.0, 5.4 and 5.0 in EGEA and 7.2, 0.7 and 4.8 in BAMSE). CONCLUSION: The A+R+ phenotype combined the sensitization pattern of both the A-R+ and A+R- phenotypes. This multimorbid polysensitized phenotype seems to be generalizable to various ages and allergenic environments and may be associated with specific mechanisms.

LR12-peptide quantitation in whole blood by RP-HPLC and intrinsic fluorescence detection: Validation and pharmacokinetic study.

A simple, sensitive, selective and robust HPLC method based on intrinsic fluorescence detection was developed for the quantitation of a dodecapeptide (designated as LR12), inhibitor of Triggering Receptor Expressed on Myeloid cells-1, in rat whole blood. Sample treatment was optimized using protein precipitation and solid-phase extraction. Chromatographic separation was carried out in a gradient mode using a core-shell C18 column (150 × 4.6 mm, 3.6 µm) with mobile phases of acetonitrile and water containing trifluoroacetic acid at 1.0 mL/min. The method was validated using methodology described by the US Food and Drug Administration guidelines for bioanalytical methods. Linearity was demonstrated within the 50-500 ng/mL range and the lower limit of quantitation was 50 ng/mL. Finally, a preliminary pharmacokinetic study after intraperitoneal injection of LR12 in rats was conducted to evaluate both LR12 monomer and its corresponding disulfide dimer, the main product of degradation. Beyond the fact that this paper describes the first fully validated method for LR12 analysis in blood samples, the approach followed here to optimize pre-analytical steps could be beneficial to develop HPLC and/or MS methods for other pharmaceutical peptides.

[Hydrogen sulfide: A promising therapy in neuroprotection following cardiac arrest?]. / Le sulfure d'hydrogène : une thérapeutique d'avenir dans la neuroprotection post-arrêt cardiorespiratoire ?

Each year, in France, the number of cardiac arrests is evaluated between 30,000 to 50,000. When a patient survives, he undergoes a post-resuscitation syndrome which can aggravate the injuries and for which nowadays, no medication is available. In some kinds of cardiac arrest, a hypothermia protocol can be applied with a need for monitoring because of the appearance of side effects. In this context, hydrogen sulfide, which is a gasotransmitter with numerous physiological and pharmacological properties, may be interesting. Indeed, its use could protect against oxidative, inflammatory and apoptotic troubles induced by the post-resuscitation syndrome. The implied biochemical mechanisms are adenosine triphosphate potassium channels activation and cytochrome c oxidase inhibition. This molecule can also induce a suspended animation state characterized by a metabolism decrease, which could give a delay for physicians to start a therapeutic monitoring. Thus, in spite of a modest and sometimes contradictory literature, this compound could become the first neuroprotective molecule in cardiac arrest.

[Genetic and environmental factors of asthma and allergy: Results of the EGEA study]. / Facteurs génétiques et environnementaux de l'asthme et de l'allergie: synthèse des résultats de l'étude EGEA.

INTRODUCTION AND METHODS: The EGEA study (epidemiological study on the genetics and environment of asthma, bronchial hyperresponsiveness and atopy), which combines a case-control and a family-based study of asthma case (n=2120 subjects) with three surveys over 20 years, aims to identify environmental and genetic factors associated with asthma and asthma-related phenotypes. We summarize the results of the phenotypic characterization and the investigation of environmental and genetic factors of asthma and asthma-related phenotypes obtained since 2007 in the EGEA study (42 articles). RESULTS: Both epidemiological and genetic results confirm the heterogeneity of asthma. These results strengthen the role of the age of disease onset, the allergic status and the level of disease activity in the identification of the different phenotypes of asthma. The deleterious role of active smoking, exposure to air pollution, occupational asthmogenic agents and cleaning products on the prevalence and/or activity of asthma has been confirmed. Accounting for gene-environment interactions allowed the identification of new genetic factors underlying asthma and asthma-related traits and better understanding of their mode of action. CONCLUSION: The EGEA study is contributing to the advances in respiratory research at the international level. The new phenotypic, environmental and biological data available in EGEA study will help characterizing the long-term evolution of asthma and the factors associated to this evolution.

[Which future in cardiovascular therapy for nitric oxide and its derivatives?]. / Quel avenir en thérapeutique cardiovasculaire pour le monoxyde d'azote et ses dérivés?

Nitric oxide (NO) is involved in the regulation of several physiological processes such as vascular homeostasis. Exogenous NO supply offers major therapeutic interest, especially in the treatment of coronary artery disease, ischemic syndromes and other cardiovascular pathologies. Nevertheless, the administration of NO itself is limited by its short half-life. NO prodrugs have been marketed for decades, e.g. organic nitrates for angina pectoris. These prodrugs display undeniable advantages such as angina crisis relief and preconditioning effect. Nevertheless, they suffer from several drawbacks: toxicity, tolerance, endothelial dysfunction exacerbation. These negative effects are related to massive production of reactive species derived from oxygen or nitrogen, which trigger oxidative and nitrosative stress. New NO donors are under development to overcome those disadvantages, among which the S-nitrosothiols family seems especially promising.

Impact of gold nanoparticle coating on redox homeostasis.

Gold nanoparticles (AuNP) hold great potential for biomedical applications. This study was aimed at examination of the effect of AuNP coating on the redox status of their environment. Two kinds of AuNP were tested, similar by shape and size, but with different surface coatings: either stabilized with citrate or functionalized with dihydrolipoic acid (Au@DHLA NP). Interestingly, whereas citrate-stabilized AuNP interact in vitro with reduced glutathione (GSH) and S-nitrosoglutathione, Au@DHLA NP do not interfere with both biomolecules. Albumin exhibits higher affinity toward citrate-stabilized AuNP than Au@DHLA NP, increasing their hydrodynamic diameter (8.0- and 1.3-fold, respectively). Furthermore, the AuNP coating affects also their internalization by macrophages (which was two fold higher for citrate-stabilized AuNP), following an exposure to a subtoxic NP concentration (10 nM, 80% viability). Citrate-stabilized AuNP were found to decrease the intracellular GSH level (ca. 20%), with no increase in reactive oxygen species production. Furthermore, these AuNP did not induce apoptosis (as shown by caspase-3 activity and nfkb2 transcription factor), and also did not activate gene expression related to oxidative stress (ncf1) and inflammatory response (tnfα). The present data highlight that the functionalization of AuNP with DHLA decreases their reactivity with biomolecules and cells, resulting in a promising medical platform.

Identifying adult asthma phenotypes using a clustering approach.

There is a need to improve asthma characterisation by integrating multiple aspects of the disease. The aim of the present study was to identify distinct asthma phenotypes by applying latent class analysis (LCA), a model-based clustering method, to two large epidemiological studies. Adults with asthma who participated in the follow-up of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA2) (n = 641) and the European Community Respiratory Health Survey (ECRHSII) (n = 1,895) were included. 19 variables covering personal characteristics, asthma symptoms, exacerbations and treatment, age of asthma onset, allergic characteristics, lung function and airway hyperresponsiveness were considered in the LCA. Four asthma phenotypes were distinguished by the LCA in each sample. Two phenotypes were similar in EGEA2 and ECRHSII: active treated allergic childhood-onset asthma and active treated adult-onset asthma. The other two phenotypes were composed of subjects with inactive or mild untreated asthma, who differed by atopy status and age of asthma onset (childhood or adulthood). The phenotypes clearly discriminated populations in terms of quality of life, and blood eosinophil and neutrophil counts. The LCAs revealed four distinct asthma phenotypes in each sample. Considering these more homogeneous phenotypes in future studies may lead to a better identification of risk factors for asthma.

Quality-of-life and asthma-severity in general population asthmatics: results of the ECRHS II study.

BACKGROUND: Health-related quality-of-life (HRQL) has been poorly studied in large samples of asthmatics from the general population. HRQL and its relationship to asthma-severity were assessed among 900 asthmatics enrolled in the European Community Respiratory Health Survey. METHODS: Among asthmatics, 864 completed the short form-36 (SF-36) questionnaire and 477 also completed the Asthma Quality-of-life Questionnaire (AQLQ). A 4-class asthma-severity scale, combining clinical items, forced expiratory volume in 1 s and the level of treatment and the different asthma-severity components (each of the clinical items and hospitalization) were studied in relation to HRQL. RESULTS: Mean SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores (45.5 and 48.8 respectively) were lower than expected in a general population. The mean total AQLQ score was 5.8. The AQLQ score and to a lesser extent the PCS score were significantly related to the 4-class asthma-severity scale, although the risk of having a lower HRQL score did not vary proportionally across the levels of severity. Asthma-severity had no impact on the MCS score. Asthma attack frequency and hospitalization were associated with both total AQLQ and PCS scores, whereas nocturnal symptoms and lung function were more strongly related to the AQLQ and PCS score respectively. CONCLUSION: In population-based asthmatics, the specific AQLQ questionnaire, and also to a lesser extent the generic SF-36 questionnaire, were sensitive to asthma-severity. Frequencies of asthma attacks, of nocturnal symptoms and hospitalization for asthma have independent impact on HRQL.

Stereoselective preparation and reactions of configurationally defined dialkylzinc compounds

The reaction of cyclic and open-chain diastereomerically pure secondary organoboranes with diisopropylzinc allows the preparation of secondary dialkylzinc reagents with good to excellent retention of configuration as shown by deuterolysis and CuI- and Pd0-mediated reactions with electrophiles. The importance of a high boron-zinc exchange rate to obtain high diastereoselectivity has been shown. Improvement of the configurational stability and stereomeric purity of the zinc intermediates has been obtained by using mono-isopinocampheylborane ((-)-IpcBH2) providing optically active dialkylzinc compounds (up to 96% ee) with enhanced diastereoselectivities.

Dopamine receptors: selective agonists and antagonists of functionally distinct types within the feline brain.

Unilateral injections of agents that are useful tools for differentiating electrophysiologically distinct dopamine receptors within the snail Helix aspersa are given into behaviourally distinct dopamine sensitive areas within the caudate nucleus of cats. Dopamine-elicited contralateral head-turning is selectively mimicked by apomorphine and selectively inhibited by haloperidol, whereas dopamine-elicited homolateral head-turning including oro-facial dyskinesias is selectively mimicked by (3, 4-dihydroxy-phenylamino)-2-imidazoline (DPI) and selectively inhibited by ergometrine, piribedil and noradrenaline. These results indicate that the caudate nucleus of cats contains two functionally and pharmalogically distinct dopamine receptors and that Helix aspersa dopamine sensitive neurons can be used as model for the design of drugs selectively interfering with each type of receptor. The implications of these findings are considered in view of the efficacy of piribedil, L-DOPA and neuroleptics in psychomotor diseases in man.