Novel polycarboxylate porphyrins: synthesis, characterization, photophysical properties and preliminary antimicrobial study against Gram-positive bacteria.

We describe the synthesis, characterization and photophysical properties of two new polycarboxylic photosensitizers. Owing to their structural design, these two compounds show water solubilities larger than natural carboxylic photosensitizers (e.g., protoporphyrin IX, hematoporphyrin, etc.) and also good singlet oxygen quantum yields. These compounds were tested as photo-antimicrobial agents against Staphylococcus aureus and Bacillus cereus strains. Results reveal that their photocytotoxicities are strongly dependent on their amphiphilic character and more precisely the number and position of the carboxylic acid and mesityl substituents.

Characterization of lipoteichoic acid structures from three probiotic Bacillus strains: involvement of D-alanine in their biological activity.

Probiotics represent a potential strategy to influence the host's immune system thereby modulating immune response. Lipoteichoic Acid (LTA) is a major immune-stimulating component of Gram-positive cell envelopes. This amphiphilic polymer, anchored in the cytoplasmic membrane by means of its glycolipid component, typically consists of a poly (glycerol-phosphate) chain with D-alanine and/or glycosyl substitutions. LTA is known to stimulate macrophages in vitro, leading to secretion of inflammatory mediators such as Nitric Oxide (NO). This study investigates the structure-activity relationship of purified LTA from three probiotic Bacillus strains (Bacillus cereus CH, Bacillus subtilis CU1 and Bacillus clausii O/C). LTAs were extracted from bacterial cultures and purified. Chemical modification by means of hydrolysis at pH 8.5 was performed to remove D-alanine. The molecular structure of native and modified LTAs was determined by (1)H NMR and GC-MS, and their inflammatory potential investigated by measuring NO production by RAW 264.7 macrophages. Structural analysis revealed several differences between the newly characterized LTAs, mainly relating to their D-alanylation rates and poly (glycerol-phosphate) chain length. We observed induction of NO production by LTAs from B. subtilis and B. clausii, whereas weaker NO production was observed with B. cereus. LTA dealanylation abrogated NO production independently of the glycolipid component, suggesting that immunomodulatory potential depends on D-alanine substitutions. D-alanine may control the spatial configuration of LTAs and their recognition by cell receptors. Knowledge of molecular mechanisms behind the immunomodulatory abilities of probiotics is essential to optimize their use.

[Translation of the Occupational Balance Questionnaire in French and its Validation]. / Traduction de l'Occupational Balance Questionnaire en français et sa validation.

Background. Questionnaires measuring occupational balance have been created in recent years, but those available in French are limited. Purpose. This study aimed to translate and transculturally adapt the Occupational Balance Questionnaire and to examine the internal consistency, test-retest reliability and convergent validity of the French version. Methodology. A cross-cultural validation was conducted with adults in Quebec (n = 69) and in French-speaking Switzerland (n = 47). Results. Internal consistency was good in both regions (α > 0.85). Test-retest reliability was satisfactory in Quebec (ICC = 0.629; p < 0.001), but a significant difference was found between the two measurement times in French-speaking Switzerland. Significant associations were found between the results of the Occupational Balance Questionnaire and those of the Life Balance Inventory (Quebec, r = 0.47; French-speaking Switzerland, r = 0.52). Implications. These initial results support the use of the OBQ-French in the general population of two French-speaking regions.

Description. Des questionnaires visant à mesurer l'équilibre occupationnel ont été créés ces dernières années, mais ceux disponibles en français sont limités. But. Cette étude visait à traduire et adapter transculturellement l'Occupational Balance Questionnaire et à examiner la cohérence interne, la fidélité test-retest et la validité convergente de la version en français. Méthodologie. Une validation a été effectuée auprès de personnes adultes au Québec (n = 69) et en Suisse romande (n = 47). Résultats. La cohérence interne est bonne dans les deux régions (α > 0,85). La fidélité test-retest est satisfaisante au Québec (ICC = 0,629 ; p < 0,001), mais une différence significative est relevée entre deux passations en Suisse romande. Une relation significative est démontrée entre l'équilibre occupationnel et l'équilibre de vie (Québec r = 0,47 ; Suisse romande r = 0,52). Conséquences. Ces premiers résultats soutiennent l'utilisation de l'OBQ-français auprès de la population générale de deux régions francophones.

Optimized Single-Step Recovery of Lipophilic and Hydrophilic Compounds from Raspberry, Strawberry and Blackberry Pomaces Using a Simultaneous Ultrasound-Enzyme-Assisted Extraction (UEAE).

An ultrasound-enzyme-assisted extraction (UEAE) was optimized to extract, simultaneously, the hydrophilic and lipophilic compounds from three berry pomaces (raspberry, strawberry and blackberry). First, an enzyme screening designated a thermostable alkaline protease as the most suitable enzyme to recover, in an aqueous medium, the highest yields of polyphenols and oil in the most efficient way. Secondly, the selected enzyme was coupled to ultrasounds (US) in sequential and simultaneous combinations. The simultaneous US-alkaline enzyme combination was selected as a one-single-step process and was then optimized by definitive screening design (DSD). The optimized parameters were: US amplitude, 20% (raspberry pomace) or 70% (strawberry and blackberry pomaces); pH, 8; E/S ratio, 1% (w/w); S/L ratio, 6% (w/v); extraction time, 30 min; temperature, 60 °C. Compared to conventional extractions using organic solvents, the UEAE extracted all the polyphenols, with around 75% of the active polyphenols (measured by the DPPH● method) and up to 75% of the initial oil from the berry pomaces. Characterized lipophilic compounds were rich in polyunsaturated fatty acids (PUFAs), tocols and phytosterols. The polyphenolics were analyzed by UPLC-MS/MS; characteristic ellagitannins of the Rosaceae family (sanguiin H-6 or agrimoniin, sanguiin H-10, …) and ellagic acid conjugates were found as the major components.

Reasons French drivers gave for committing or refusing to commit to complying with speed limits at rehabilitation training courses for traffic-regulation offenders.

A mixed foot-in-the-door procedure was set up to lead offenders participating in French driver-rehabilitation training courses to commit to complying with speed limits. To improve this procedure, the reasons that led participants in such courses to commit or not were investigated in this preliminary study of the road safety research programs. The study participants were 89 men (M=34 yr., range = 18-64 yr., SD=13) attending driver-rehabilitation courses. Among them, 55% committed. The commitment was mainly explained by the drivers' will to change their speeding behaviour and their refusal by the perceived positive consequences of speeding. Moreover, some participants stated that they would be unable to follow through with the commitment to comply strictly with speed limits. After talking to the participants, it became clear that complying with speed limits was understood in a more or less strict way. In subsequent studies, some of the reasons given were used to prompt group discussion before asking participants to commit, and the meaning of "compliance with speed limits" was better defined.

Enhancement of photobactericidal activity of chlorin-e6-cellulose nanocrystals by covalent attachment of polymyxin B.

Despite the advances made over the last decade, infections caused by multi-drug resistant bacterial strains are increasingly important societal issues that need to be addressed. New approaches have already been developed in order to overcome this problem. Photodynamic antimicrobial chemotherapy (PACT) could provide an alternative to fight infectious bacteria. This approach has already inspired the development of innovative materials. Interesting results have been obtained against Gram-positive bacteria, but it also appeared that Gram-negative strains, especially Pseudomonas aeruginosa, were less sensitive to PACT. Enhanced efficacy against Gram-negative bacteria had been previously obtained with photosensitizers bound to antimicrobial peptides. In this work, we designed a photobactericidal organic material, CNCsc6-PMB, consisting of cellulose nanocrystals to which the photosensitizer chlorin-e6 and the antimicrobial polypeptide polymyxin B (PMB) were covalently attached. These modified nanocrystals were characterized by IR spectroscopy, zeta potential measurements and elemental analyses, after which antibacterial assays were carried out. Following light irradiation, CNCsc6-PMB demonstrated efficiency against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) by inhibition of bacterial growth. An amplifying effect of chlorin-e6 has been highlighted against these Gram-negative strains, based on membrane weakening and a potential docking effect from the polymyxin moiety. Such results confirmed the importance of using an antimicrobial peptide in order to broaden the spectrum of PACT.