124 research outputs found

    Chemical composition, antioxidant and anti-AGEs activities of a French propolis

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    Accumulation in tissues and serum of advanced glycation end-products (AGEs) plays an important role in pathologies such as Alzheimer\u27s disease or, in the event of complications of diabetes, atherosclerosis or renal failure. Therefore there is a potential therapeutic interest in natural antioxidants with true anti-AGEs capabilities for the prevention of this kind of pathologies. The aim of this study was to evaluate the antioxidant and anti-AGEs potential of a French propolis batch (natural resinous substance collected by honeybees from differents plants and trees), then to identify the main compounds responsible for this anti-AGEs effect. For this purpose, the phytochemical composition of a 70% ethanolic extract of propolis (EEP70) was determined, using HPLC/DAD/MS and/or 1H and 13C NMR (1D and 2D) analysis. This study showed the presence of phenolic acids and their esters as well as flavonoids. Then, the evaluation of the antioxidant, using DPPH and ORAC assays, and the anti-AGEs potential, using an automated test recently developed in our laboratory, showed that EEP70 exhibited both high antioxidant (1650 ± 149 ”mol TE/g) and anti-AGEs (IC50=0.03 mg/ml) activities. A bio-guided fractionation allowed us to identify the most active anti-AGEs compounds: pinobanksin-3-acetate (IC50=0.06 mM) which is the major compound of EEP70. Thus, EEP70 represents a good candidate as food additive to prevent glycoxidation. Boisard S, Le Ray A-M, Gatto J, Aumond M-C, Blanchard P, DerbrĂ© S, Flurin C, Richomme P: Chemical Composition, Antioxidant and Anti-AGEs Activities of a French Poplar Type Propolis. J Agric Food Chem 2014, 62:1344–1351

    PropriĂ©tĂ©s antibactĂ©riennes d’extraits de propolis contre des souches de Staphylococcus aureus sensibles ou rĂ©sistantes Ă  la mĂ©thicilline

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    La rĂ©sistance aux antibiotiques est devenue l\u27un des problĂšmes majeurs de santĂ© publique du XXIĂšme siĂšcle. Il existe donc un rĂ©el intĂ©rĂȘt thĂ©rapeutique dans la recherche de composĂ©s ou d\u27extraits naturels capables de limiter cette rĂ©sistance. La propolis est un mĂ©lange complexe composĂ© de substances rĂ©sineuses collectĂ©es par les abeilles sur diffĂ©rentes parties des plantes et arbres, de cires et de sĂ©crĂ©tions salivaires de l\u27abeille. Elle sert principalement Ă  colmater les interstices des parois de la ruche et comme vĂ©ritable arme chimique contre les microorganismes. La propolis est utilisĂ©e depuis longtemps en mĂ©decine traditionnelle puisqu\u27elle possĂšde des propriĂ©tĂ©s pharmacologiques intĂ©ressantes notamment antioxydante, anti-inflammatoire mais aussi antimicrobienne. Un Ă©chantillon de propolis, composĂ© de 24 lots collectĂ©s en France (majoritairement dans le sud-ouest) en 2010 et 2011, a Ă©tĂ© extrait par diffĂ©rents solvants : EtOH 70%, MeOH, DCM et DCM/MeOH/eau 31/19/4 (mixte). La composition chimique des extraits a prĂ©alablement Ă©tĂ© dĂ©terminĂ©e au moyen d’analyses HPLC/DAD/MS et RMN 1H et 13C. L\u27activitĂ© antibactĂ©rienne a Ă©tĂ© Ă©valuĂ©e sur des bactĂ©ries responsables d\u27infections nosocomiales, et plus spĂ©cifiquement sur 13 souches de Staphylococcus aureus [ATCC25923, six isolats cliniques de souches rĂ©sistantes Ă  la mĂ©thiciline (SARM) et six isolats cliniques de souches sensibles Ă  la mĂ©thiciline (SASM)] par dĂ©termination de la concentration minimum d\u27inhibition (CMI) en milieu gĂ©losĂ© [1]. Les rĂ©sultats ont montrĂ© que, parmi les quatre extraits, le DCM et le "mixte" prĂ©sentaient une bonne activitĂ© antibactĂ©rienne contre S. aureus (SA) avec des CMI respectives de 60±10 et 67±15 ”g/mL mais Ă©galement sur quasiment toutes les souches SARM et SASM testĂ©es (CMI entre 30 et 97 ”g/mL). Ces bonnes activitĂ©s des extraits DCM et mixte peuvent ĂȘtre reliĂ©es Ă  des teneurs Ă©levĂ©es en polyphĂ©nols totaux et en flavonoĂŻdes [1]. Diverses Ă©tudes ont en effet montrĂ© que ce type de mĂ©lange complexe, riche en polyphĂ©nols, Ă©tait plus actif que les composĂ©s isolĂ©s les constituant. Les polyphĂ©nols agiraient ainsi de façon synergique, potentialisant l\u27activitĂ© antibactĂ©rienne de ces extraits [2]. D\u27autres Ă©tudes, menĂ©es in vitro, ont par ailleurs mis en Ă©vidence un rĂ©el synergisme entre propolis et antibiotiques [3], [4]. Ainsi, ces extraits de propolis prĂ©sentent-ils un rĂ©el potentiel dans une lutte alternative contre des infections Ă  staphylocoques.   RĂ©fĂ©rences [1]          S. Boisard et al., "Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis", Evid. Based Complement. Alternat. Med., vol. 2015, p. e319240, 2015. [2]          A. Kujumgiev, I. Tsvetkova, Y. Serkedjieva, V. Bankova, R. Christov, et S. Popov, "Antibacterial, antifungal and antiviral activity of propolis of different geographic origin", J. Ethnopharmacol., vol. 64, no 3, p. 235‑240, 1999. [3]          S. Stepanović, N. Antić, I. Dakić, et M. Ć vabić-Vlahović, "In vitro antimicrobial activity of propolis and synergism between propolis and antimicrobial drugs", Microbiol. Res., vol. 158, no 4, p. 353‑357, 2003. [4]          A. Fernandes JĂșnior, E. C. Balestrin, J. E. C. Betoni, R. de O. Orsi, M. de L. R. de S. da Cunha, et A. C. Montelli, "Propolis: anti-Staphylococcus aureus activity and synergism with antimicrobial drugs", Mem. Inst. Oswaldo Cruz, vol. 100, no 5, p. 563‑566, 2005

    Rotator cuff tears after 70years of age: A prospective, randomized, comparative study between decompression and arthroscopic repair in 154 patients

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    SummaryIntroductionArthroscopic repair of rotator cuff tears leads to better clinical outcomes than subacromial decompression alone; however the former is rarely proposed to patients above 70years of age. Our hypothesis was that arthroscopic repair would be superior to decompression in patient 70years or older. The primary goal was to compare the clinical results obtained with each technique. The secondary goal was to analyze the effects of age, tendon retraction and fatty infiltration on the outcome.MethodsThis was a prospective, comparative, randomized, multicenter study where 154 patients were included who were at least 70years of age. Of the included patients, 143 (70 repair and 73 decompression) were seen at one-year follow-up; these patients had an average age of 74.6years. Shoulders had a complete supraspinatus tear with extension limited to the upper-third of the infraspinatus and Patte stage 1 or 2 retraction. Clinical outcomes were evaluated with the Constant, ASES and SST scores.ResultsAll scores improved significantly with both techniques: Constant +33.81 (P<0.001), ASES +52.1 (P<0.001), SST +5.86 (P<0.001). However, repair led to even better results than decompression: Constant (+35.85 vs. +31.8, P<0.05), ASES (+56.09 vs. +48.17, P=0.01), SST (+6.33 vs. +5.38, P=0.02). The difference between repair and decompression was not correlated with age; arthroscopic repair was also better in patients above 75years of age (Constant, ASES and SST scores P<0.01). There was no significant correlation between the final outcomes and initial retraction: Constant (P=0.14), ASES (P=0.92), SST (P=0.47). The difference between repair and decompression was greater in patients with stages 0 and 1 fatty infiltration (Constant P<0.02) than in patients with stages 2 and 3 fatty infiltration (Constant P<0.05).ConclusionThere was a significant improvement in all-clinical scores for both techniques 1year after surgery. Repair was significantly better than decompression for all clinical outcomes, even in patients above 75years of age. The difference observed between repair and decompression was greater in patients with more retracted tears and lesser in patients with more severe fatty infiltration.Level of proofII (prospective, randomized study with low power)

    Twentieth Century Redistribution in Climatic Drivers of Global Tree Growth

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    Energy and water limitations of tree growth remain insufficiently understood at large spatiotemporal scales, hindering model representation of interannual or longer-term ecosystem processes. By assessing and statistically scaling the climatic drivers from 2710 tree-ring sites, we identified the boreal and temperate land areas where tree growth during 19301960 CE responded positively to temperature (20.8 3.7 Mio km2; 25.9 4.6%), precipitation (77.5 3.3 Mio km2; 96.4 4.1%), and other parameters. The spatial manifestation of this climate response is determined by latitudinal and altitudinal temperature gradients, indicating that warming leads to geographic shifts in growth limitations. We observed a significant (P < 0.001) decrease in temperature response at cold-dry sites between 19301960 and 19601990 CE, and the total temperature-limited area shrunk by 8.7 0.6 Mio km2. Simultaneously, trees became more limited by atmospheric water demand almost worldwide. These changes occurred under mild warming, and we expect that continued climate change will trigger a major redistribution in growth responses to climate

    Polyphenolic content and pharmacological potential of french BFA propolis extracts

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    Propolis, or bee glue, is a natural resinous hive product collected by honeybees from buds and exudates of various trees and plants. Mixed with beewax and salivary enzymes, it is employed to fill cracks and embalm dead invaders in the hive. Propolis has been used in folk medecine since ancien times due to its pharmacological potential associated with antioxidant, antifungal, antibacterial as well as antitumoral properties. A batch of various French propolis extracts, supplied by “Ballot-Flurin Apiculteurs” (BFA), a company located in the South-West of France and specialized in apitherapy products, was fractionated and analysed by HPLC/MS. Its qualitative chemical composition highlights the presence of polyphenols such as hydroxycinnamic acid derivatives and flavonoids. Total polyphenol content and antioxidant activities were evaluated on six BFA propolis extracts, using respectively Folin-Ciocalteu, DPPH and ORAC assays. Preliminary antifungal (Candida albicans) and antibacterial (Staphylococcus aureus) evaluations will also be given

    Hearing Loss in Cancer Patients with Skull Base Tumors Undergoing Pencil Beam Scanning Proton Therapy: A Retrospective Cohort Study.

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    To assess the incidence and severity of changes in hearing threshold in patients undergoing high-dose pencil-beam-scanning proton therapy (PBS-PT). This retrospective cohort study included fifty-one patients (median 50 years (range, 13-68)) treated with PBS-PT for skull base tumors. No chemotherapy was delivered. Pure tone averages (PTAs)were determined before (baseline) and after PBS-PT as the average hearing thresholds at frequencies of 0.5, 1, 2, and 4 kHz. Hearing changes were calculated as PTA differences between pre-and post-PBS-PT. A linear mixed-effects model was used to assess the relationship between the PTA at the follow-up and the baseline, the cochlea radiation dose intensity, the increased age, and the years after PBS-PT. Included patients were treated for chordoma (n = 24), chondrosarcoma (n = 9), head and neck tumors (n = 9), or meningioma (n = 3), with a mean tumor dose of 71.1 Gy (RBE) (range, 52.0-77.8), and a mean dose of 37 Gy (RBE) (range, 0.0-72.7) was delivered to the cochleas. The median time to the first follow-up was 11 months (IQR, 5.5-33.7). The PTA increased from a median of 15 dB (IQR 10.0-25) at the baseline to 23.8 (IQR 11.3-46.3) at the first follow-up. In the linear mixed-effect model, the baseline PTA (estimate 0.80, 95%CI 0.64 to 0.96, p ≀ 0.001), patient's age (0.30, 0.03 to 0.57, p = 0.029), follow-up time (2.07, 0.92 to 3.23, p ≀ 0.001), and mean cochlear dose in Gy (RBE) (0.34, 0.21 to 0.46, p ≀ 0.001) were all significantly associated with an increase in PTA at follow-up. The applied cochlear dose and baseline PTA, age, and time after treatment were significantly associated with hearing loss after proton therapy

    High-Precision Mass-Dependent Molybdenum Isotope Variations in Magmatic Rocks Determined by Double-Spike MC-ICP-MS

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    Small mass‐dependent variations of molybdenum isotope ratios in oceanic and island arc rocks are expected as a result of recycling altered oceanic crust and sediments into the mantle at convergent plate margins over geological timescales. However, the determination of molybdenum isotope data precise and accurate enough to identify these subtle isotopic differences remains challenging. Large sample sizes – in excess of 200 mg – need to be chemically processed to isolate enough molybdenum in order to allow sufficiently high‐precision isotope analyses using double‐spike MC‐ICP‐MS techniques. Established methods are either unable to process such large amounts of silicate material or require several distinct chemical processing steps, making the analyses very time‐consuming. Here, we present a new and efficient single‐pass chromatographic exchange technique for the chemical isolation of molybdenum from silicate and metal matrices. To test our new method, we analysed USGS reference materials BHVO‐2 and BIR‐1. Our new data are consistent with those derived from more involved and time‐consuming methods for these two reference materials previously published. We also provide the first molybdenum isotope data for USGS reference materials AGV‐2, the GSJ reference material JB‐2 as well as metal NIST SRM 361.ISSN:1639-4488ISSN:1751-908

    Hearing Loss in Cancer Patients with Skull Base Tumors Undergoing Pencil Beam Scanning Proton Therapy: A Retrospective Cohort Study

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    To assess the incidence and severity of changes in hearing threshold in patients undergoing high-dose pencil-beam-scanning proton therapy (PBS-PT). This retrospective cohort study included fifty-one patients (median 50 years (range, 13–68)) treated with PBS-PT for skull base tumors. No chemotherapy was delivered. Pure tone averages (PTAs)were determined before (baseline) and after PBS-PT as the average hearing thresholds at frequencies of 0.5, 1, 2, and 4 kHz. Hearing changes were calculated as PTA differences between pre-and post-PBS-PT. A linear mixed-effects model was used to assess the relationship between the PTA at the follow-up and the baseline, the cochlea radiation dose intensity, the increased age, and the years after PBS-PT. Included patients were treated for chordoma (n = 24), chondrosarcoma (n = 9), head and neck tumors (n = 9), or meningioma (n = 3), with a mean tumor dose of 71.1 Gy (RBE) (range, 52.0–77.8), and a mean dose of 37 Gy (RBE) (range, 0.0–72.7) was delivered to the cochleas. The median time to the first follow-up was 11 months (IQR, 5.5–33.7). The PTA increased from a median of 15 dB (IQR 10.0–25) at the baseline to 23.8 (IQR 11.3–46.3) at the first follow-up. In the linear mixed-effect model, the baseline PTA (estimate 0.80, 95%CI 0.64 to 0.96, p ≀ 0.001), patient’s age (0.30, 0.03 to 0.57, p = 0.029), follow-up time (2.07, 0.92 to 3.23, p ≀ 0.001), and mean cochlear dose in Gy (RBE) (0.34, 0.21 to 0.46, p ≀ 0.001) were all significantly associated with an increase in PTA at follow-up. The applied cochlear dose and baseline PTA, age, and time after treatment were significantly associated with hearing loss after proton therap
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