Étude de l'impact des classes de sirop d'érable sur leurs propriétés physicochimiques pendant l'entreposage et leur comportement à l'ébullition et au refroidissement

Les produits de l'érable sont fabriqués généralement par ébullition, refroidissement, puis agitation du sirop d'érable « Canada catégorie A ». Les cristaux de sucrose formés donnent la texture au produit. En confiserie, la courbe d'élévation du point d'ébullition de l'eau (EPE) en fonction des solides solubles permet d'arrêter l'ébullition au niveau approprié de concentration pour le produit visé, alors que la courbe de la température de transition vitreuse selon la teneur en solides solubles permet de recommander des paramètres de refroidissement. Les outils actuels se basent principalement sur des solutions aqueuses de sucrose, mais la présence d'autres composés les influencent. Le sirop d'érable est une solution aqueuse, surtout de sucrose, mais aussi de sucre inverti, de polyphénols et de composés azotés. Leur teneur varie selon la couleur du sirop d'érable, représentée par sa classe : « Doré », « Ambré », « Foncé » ou « Très foncé ». Les caractéristiques physicochimiques pourraient changer au cours de leur entreposage. Au cours de ce projet, les effets de la durée d'entreposage sur une année et de la classe de sirop sur leurs caractéristiques physicochimiques ont été étudiés. Les teneurs en polyphénols, sucre inverti et composés azotés tendaient à être plus élevées dans les sirops plus foncés, contrairement à la concentration en sucrose qui diminuait légèrement. Au cours de l'entreposage, la teneur en sucrose augmentait, alors que les concentrations en polyphénols et le pH diminuaient. Pour mieux comprendre l'effet des classes de sirop pendant leur transformation, leur comportement a été étudié pendant l'ébullition et le refroidissement. La courbe de la température de transition vitreuse était commune à tous les sirops, tandis que celles de l'EPE variaient selon leur classe. Ces connaissances appuieront une meilleure compréhension de la cristallisation du sucrose dans un contexte de transformation du sirop d'érable.Maple products are generally made from "Canada grade A" maple syrup by boiling, cooling, and then stirring. Crystallization gives the characteristic texture to maple products. In confectionery, the Boiling point elevation (BPE) depending on total soluble solids curve is used to stop boiling at the appropriate concentration level for the intended product, while the curve of glass transition temperature depending on total soluble solids is used to recommend cooling parameters. Current tools are mainly based on aqueous solutions of sucrose, but the addition of other compounds influences them. Maple syrup is an aqueous solution, mainly composed of sucrose, but also of invert sugar, total phenolic content and nitrogenous compounds. Their content changes according to the color of the maple syrup, represented by its class: " Golden ", " Amber ", " Dark " or " Very dark ". Their physicochemical characteristics could change during storage. During this project, the effects of storage time over a year and syrup class on their physicochemical characteristics were studied. Polyphenols, invert sugar and nitrogen compounds tended to be higher in darker syrups, while the sucrose concentration decreased slightly. During storage, sucrose content increased, while polyphenol concentrations and pH decreased. To better understand the effect of the syrup classes during processing, their behavior during boiling and cooling was studied. The glass transition temperature curve was common to all syrups, while the BPE curves varied according to their class. This knowledge will be used to better understand sucrose crystallization in a maple syrup processing context

Protective effect of probiotics on Salmonella infectivity assessed with combined in vitro gut fermentation-cellular models

<p>Abstract</p> <p>Background</p> <p>Accurate assessment of probiotics with targeted anti-<it>Salmonella </it>activity requires suitable models accounting for both, microbe-microbe and host-microbe interactions in gut environments. Here we report the combination of two original <it>in vitro </it>intestinal models closely mimicking the complex <it>in vivo </it>conditions of the large intestine. Effluents from continuous <it>in vitro </it>three-stage fermentation colonic models of <it>Salmonella </it>Typhimurium infection inoculated with immobilized child microbiota and <it>Salmonella </it>were directly applied to confluent mucus-secreting HT29-MTX cell layers. The effects of <it>Salmonella</it>, addition of two bacteriocinogenic strains, <it>Bifidobacterium thermophilum </it>RBL67 (thermophilicin B67) and <it>Escherichia coli </it>L1000 (microcin B17), and inulin were tested on <it>Salmonella </it>growth and interactions with epithelial cell layers. <it>Salmonella </it>adhesion and invasion were investigated and epithelial integrity assessed by transepithelial electrical resistance (TER) measurements and confocal microscopy observation. Data from complex effluents were compared with pure <it>Salmonella </it>cultures.</p> <p>Results</p> <p><it>Salmonella </it>in effluents of all reactors of the colonic fermentation model stabilized at mean values of 5.3 ± 0.8 log₁₀cfu/ml effluent. Invasion of cell-associated <it>Salmonella </it>was up to 50-fold lower in complex reactor samples compared to pure <it>Salmonella </it>cultures. It further depended on environmental factors, with 0.2 ± 0.1% being measured with proximal, 0.6 ± 0.2% with transverse and 1.3 ± 0.7% with distal reactor effluents, accompanied by a similar high decrease of TER across cell monolayers (minus 45%) and disruption of tight junctions. Subsequent addition of <it>E. coli </it>L1000 stimulated <it>Salmonella </it>growth (6.4 ± 0.6 log₁₀cfu/ml effluent of all 3 reactors) and further decreased TER, but led to 10-fold decreased invasion efficiency when tested with distal reactor samples. In contrast, presence of <it>B. thermophilum </it>RBL67 revealed a protective effect on epithelial integrity compared to previous <it>E. coli </it>L1000 periods, as reflected by a significant mean increase of TER by 58% in all reactors. Inulin addition enhanced <it>Salmonella </it>growth and invasion when tested with distal and proximal reactor samples, respectively, but induced a limited decrease of TER (minus 18%) in all reactors.</p> <p>Conclusions</p> <p>Our results highlight the benefits of combining suitable cellular and colonic fermentation models to assess strain-specific first-level host protection properties of probiotics during <it>Salmonella </it>infection, providing an efficient system biology tool for preclinical development of new antimicrobials.</p

Widespread occurrence of chromosomal aneuploidy following the routine production of Candida albicans mutants

It has come to our attention that approximately 35% of >100 published microarray datasets, where transcript levels were compared between two different strains, exhibit some form of chromosome-specific bias. While some of these arose from the use of strains whose aneuploidies were not known at the time, in a worrisome number of cases the recombinant strains have acquired additional aneuploidies that were not initially present in the parental strain. The aneuploidies often affected a different chromosome than the one harboring the insertion site. The affected strains originated from either CAI-4, RM1000, BWP17 or SN95 and were produced through a variety of strategies. These observations suggest that aneuploidies frequently occur during the production of recombinant strains and have an effect on global transcript profiles outside of the afflicted chromosome(s), thus raising the possibility of unintended phenotypic consequences. Thus, we propose that all Candida albicans mutants and strains should be tested for aneuploidy before being used in further studies. To this end, we describe a new rapid testing method, based on a multiplex quantitative PCR assay, that produces eight bands of distinct sizes from either the left or right arms of each C. albicans chromosome

Portrait of blood-derived extracellular vesicles in patients with Parkinson's disease.

The production of extracellular vesicles (EV) is a ubiquitous feature of eukaryotic cells but pathological events can affect their formation and constituents. We sought to characterize the nature, profile and protein signature of EV in the plasma of Parkinson's disease (PD) patients and how they correlate to clinical measures of the disease. EV were initially collected from cohorts of PD (n = 60; Controls, n = 37) and Huntington's disease (HD) patients (Pre-manifest, n = 11; manifest, n = 52; Controls, n = 55) - for comparative purposes in individuals with another chronic neurodegenerative condition - and exhaustively analyzed using flow cytometry, electron microscopy and proteomics. We then collected 42 samples from an additional independent cohort of PD patients to confirm our initial results. Through a series of iterative steps, we optimized an approach for defining the EV signature in PD. We found that the number of EV derived specifically from erythrocytes segregated with UPDRS scores corresponding to different disease stages. Proteomic analysis further revealed that there is a specific signature of proteins that could reliably differentiate control subjects from mild and moderate PD patients. Taken together, we have developed/identified an EV blood-based assay that has the potential to be used as a biomarker for PD

Promoting healthy eating in early pregnancy in individuals at risk of gestational diabetes mellitus: does it improve glucose homeostasis? A study protocol for a randomized control trial

BackgroundHealthy eating during pregnancy has favorable effects on glycemic control and is associated with a lower risk of gestational diabetes mellitus (GDM). According to Diabetes Canada, there is a need for an effective and acceptable intervention that could improve glucose homeostasis and support pregnant individuals at risk for GDM.AimsThis unicentric randomized controlled trial (RCT) aims to evaluate the effects of a nutritional intervention initiated early in pregnancy, on glucose homeostasis in 150 pregnant individuals at risk for GDM, compared to usual care.MethodsPopulation: 150 pregnant individuals ≥18 years old, at ≤14 weeks of pregnancy, and presenting ≥1 risk factor for GDM according to Diabetes Canada guidelines. Intervention: The nutritional intervention initiated in the first trimester is based on the health behavior change theory during pregnancy and on Canada’s Food Guide recommendations. It includes (1) four individual counseling sessions with a registered dietitian using motivational interviewing (12, 18, 24, and 30 weeks), with post-interview phone call follow-ups, aiming to develop and achieve S.M.A.R.T. nutritional objectives (specific, measurable, attainable, relevant, and time-bound); (2) 10 informative video clips on healthy eating during pregnancy developed by our team and based on national guidelines, and (3) a virtual support community via a Facebook group. Control: Usual prenatal care. Protocol: This RCT includes three on-site visits (10–14, 24–26, and 34–36 weeks) during which a 2-h oral glucose tolerance test is done and blood samples are taken. At each trimester and 3 months postpartum, participants complete web-based questionnaires, including three validated 24-h dietary recalls to assess their diet quality using the Healthy Eating Food Index 2019. Primary outcome: Difference in the change in fasting blood glucose (from the first to the third trimester) between groups. This study has been approved by the Ethics Committee of the Centre de recherche du CHU de Québec-Université Laval.DiscussionThis RCT will determine whether a nutritional intervention initiated early in pregnancy can improve glucose homeostasis in individuals at risk for GDM and inform Canadian stakeholders on improving care trajectories and policies for pregnant individuals at risk for GDM.Clinical trial registrationhttps://clinicaltrials.gov/study/NCT05299502, NCT0529950

Short-term effects of unilateral lesion of the primary motor cortex (M1) on ipsilesional hand dexterity in adult macaque monkeys

Although the arrangement of the corticospinal projection in primates is consistent with a more prominent role of the ipsilateral motor cortex on proximal muscles, rather than on distal muscles involved in manual dexterity, the role played by the primary motor cortex on the control of manual dexterity for the ipsilateral hand remains a matter a debate, either in the normal function or after a lesion. We, therefore, tested the impact of permanent unilateral motor cortex lesion on the manual dexterity of the ipsilateral hand in 11 macaque monkeys, within a time window of 60 days post-lesion. For comparison, unilateral reversible pharmacological inactivation of the motor cortex was produced in an additional monkey. Manual dexterity was assessed quantitatively based on three motor parameters derived from two reach and grasp manual tasks. In contrast to the expected dramatic, complete deficit of manual dexterity of the contralesional hand that persists for several weeks, the impact on the manual dexterity of the ipsilesional hand was generally moderate (but statistically significant) and, when present, lasted less than 20 days. Out of the 11 monkeys, only 3 showed a deficit of the ipsilesional hand for 2 of the 3 motor parameters, and 4 animals had a deficit for only one motor parameter. Four monkeys did not show any deficit. The reversible inactivation experiment yielded results consistent with the permanent lesion data. In conclusion, the primary motor cortex exerts a modest role on ipsilateral manual dexterity, most likely in the form of indirect hand postural control

Modélisation biomécanique de l'interaction entre le corset et le tronc dans le traitement de la scoliose

Anatomie descriptive et fonctionnelle du tronc -- Déformations scoliotiques -- Traitement de la scoliose -- Évaluation du traitement par corset -- Approches de modélisation -- Simulations de l'action du corset sur le patient -- Modélisation de l'interaction patient-corset et simulation du traitement -- Objectifs et approche de modélisation -- Modélisation du tronc -- Modélisation du corset -- Modélisation des tissus mous -- Modélisation de l'interaction entre le patient et son corset -- Modélisation de l'action du corset sur le patient -- Méthodes de validation -- Résultats et validation -- Résultats associés aux bancs d'essais -- Résultats associés aux simulations sur le patient -- Analyse des résultats du banc d'essais -- Analyse des résultats des simulations avec le modèle contact -- Critique de la méthode de modélisation du traitement par corset

Partial Characterization of Bacteriocins Produced by Two New Enterococcus faecium Isolated from Human Intestine

International audienceThis study aimed at characterizing two novel bacteriocin-producing enterococcal strains isolated from human intestine. A total of 200 lactic acid bacteria were isolated from a woman stool sample. Two of them were selected for characterization due to their high antimicrobial activity against five strains of Listeria monocytogenes. The selected bacteria were identified as two different strains of Enterococcus faecium and designated MT 104 and MT 162. The bacteriocins produced by MT 104 and MT 162 were stable at different pH ranging from 2 to 11 and were active after different treatments such as heat, enzymes, detergents, and γ-irradiation. The two isolated strains exhibited some probiotic properties such as survival in simulated gastric fluid and intestinal fluid, lack of expression of bile salt hydrolase or hemolytic activity, adhesion to Caco-2 cells efficiently, and sensitivity to clinical antimicrobial agents. Thus, the two isolated strains of E. faecium could become new probiotic bacteria and their bacteriocins could be used for controlling L. monocytogenes in combination with irradiation for food preservatio

Un dépotoir du IIIe siècle apr. J.-C. dans le quartier du théâtre à Vieux (Calvados)

Demarest Mélanie, Lacroix Aurore, Thierry Marc-Antoine. Un dépotoir du IIIe siècle apr. J.-C. dans le quartier du théâtre à Vieux (Calvados). In: Aremorica. Études sur l'ouest de la Gaule romaine, n°9, 2018. pp. 39-70