Regioselective synthesis of plant (iso)flavone glycosides in Escherichia coli

The flavonoids genistein, biochanin A, luteolin, quercetin, and kaempferol are plant natural products with potentially useful pharmacological and nutraceutical activities. These natural products usually exist in plants as glycosides, and their glycosylation has a remarkable influence on their pharmacokinetic properties. The glycosyltransferases UGT71G1 and UGT73C8 from Medicago truncatula are excellent reagents for the regioselective glycosylation of (iso)flavonoids in Escherichia coli grown in Terrific broth. Ten to 20 mg/L of either genistein or biochanin A 7-O-glucoside was produced after feeding genistein or biochanin A to E. coli expressing UGT71G1, and similar levels of luteolin 4’-O- and 7-O-glucosides were produced after feeding luteolin to cultures expressing UGT73C8. For the production of kaempferol 3-O-glucoside or quercetin 3-O-glucoside, the Phe148Val or Tyr202Ala mutants of UGT71G1 were employed. Ten to 16 mg/L of either kaempferol 3-O- or quercetin 3-O-glucosides were produced on feeding kaempferol or quercetin to E. coli expressing these enzymes. More than 90% of the glucoside products were released to the medium, facilitating their isolation

Validity of absolute intake and nutrient density of protein, potassium, and sodium assessed by various dietary assessment methods:An exploratory study

It is suggested that nutrient densities are less affected by measurement errors than absolute intake estimates of dietary exposure. We compared the validity of absolute intakes and densities of protein (kJ from protein/total energy (kJ)), potassium, and sodium (potassium or sodium (in mg)/total energy (kJ)) assessed by different dietary assessment methods. For 69 Dutch subjects, two duplicate portions (DPs), five to fifteen 24-h dietary recalls (24 hRs, telephone-based and web-based) and two food frequency questionnaires (FFQs) were collected and compared to duplicate urinary biomarkers and one or two doubly labelled water measurements. Multivariate measurement error models were used to estimate validity coefficients (VCs) and attenuation factors (AFs). This research showed that group bias diminished for protein and sodium densities assessed by all methods as compared to the respective absolute intakes, but not for those of potassium. However, the VCs and AFs for the nutrient densities did not improve compared to absolute intakes for all four methods; except for the AF of sodium density (0.71) or the FFQ which was better than that of the absolute sodium intake (0.51). Thus, using nutrient densities rather than absolute intakes does not necessarily improve the performance of the DP, FFQ, or 24 hR.</p

Acoustic detection of microbubble formation induced by enhanced optical breakdown of silver/dendrimer nanocomposites

We utilize a real-time acoustic technique, based on pulse-echo measurements to detect formation of microbubbles in an aqueous solution of a silver/dendrimer nanocomposite (DNC). Wave-field plots of successive recordings illustrate the generation and behavior of bubbles created by the optical breakdown process. A significant threshold reduction is achieved with DNC particles compared to its host dendrimer, enabling a diverse field of low-threshold breakdown applications. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70570/2/APPLAB-82-6-994-1.pd

The flavonoid galangin is an inhibitor of CYP1A1 activity and an agonist/antagonist of the aryl hydrocarbon receptor

The effect of the dietary flavonoid galangin on the metabolism of 7,12-dimethylbenz[a]anthracene (DMBA), the activity of cytochrome P 450 1A1 (CYP1A1), and the expression of CYP1A1 in MCF-7 human breast carcinoma cells was investigated. Galangin inhibited the catabolic breakdown of DMBA, as measured by thin-layer chromatography, in a dose-dependent manner. Galangin also inhibited the formation of DMBA-DNA adducts, and prevented DMBA-induced inhibition of cell growth. Galangin caused a potent, dose-dependent inhibition of CYP1A1 activity, as measured by ethoxyresorufin-O-deethylase activity, in intact cells and in microsomes isolated from DMBA-treated cells. Analysis of the inhibition kinetics by double-reciprocal plot demonstrated that galangin inhibited CYP1A1 activity in a non-competitive manner. Galangin caused an increase in the level of CYP1A1 mRNA, indicating that it may be an agonist of the aryl hydrocarbon receptor, but it inhibited the induction of CYP1A1 mRNA by DMBA or by 2,3,5,7-tetrachlorodibenzo-p-dioxin (TCDD). Galangin also inhibited the DMBA- or TCDD-induced transcription of a reporter vector containing the CYP1A1 promoter. Thus, galangin is a potent inhibitor of DMBA metabolism and an agonist/antagonist of the AhR, and may prove to be an effective chemopreventive agent. © 1999 Cancer Research Campaig

Efficacy of the Gelstix nucleus augmentation device for the treatment of chronic discogenic low back pain: protocol for a randomised, sham-controlled, double-blind, multicentre trial.

INTRODUCTION Discogenic pain is the cause of pain in 26%-40% of patients with for low back pain. Consensus about treatment of chronic discogenic low back pain is lacking and most treatment alternatives are supported by limited evidence. The percutaneous implantation of hydrogels into the nucleus pulposus represents a promising regenerative intradiscal therapy. The hydrogel 'GelStix' is composed primarily of hydrolyzed polyacrylonitrile and acts as a reservoir of hydration, producing increased pressure and improved pH balance, potentially leading to disc preservation. We hypothesise that treatment with GelStix will lead to greater reduction in pain intensity at 6 months post-treatment compared with patients receiving sham treatment. METHODS AND ANALYSIS This is a parallel group, randomised sham-controlled double-blind, multicentre trial to assess whether the GelStix device is superior to sham in reducing pain intensity in patients with chronic discogenic low back pain. The study will be conducted in two regional hospitals in Europe. Seventy-two participants will be randomised in a 1:1 ratio. The primary outcome will be the change in pain intensity between preoperative baseline and at 6 months postintervention. Secondary outcomes were disability, quality of life, the patient's global impression of change scale, the use of pain medication and the disc degeneration process assessed by means of MRI. For change in pain intensity, disability, health-related quality of life and disc height, mean values will be compared between groups using linear regression analysis, adjusted for treatment centre. ETHICS AND DISSEMINATION Ethics approval was obtained from the Ethics Committee of the Canton Ticino, Switzerland (CE2982) and by the Medical Ethical Committee Arnhem-Nijmegen, the Netherlands (2016-2944). All patients that agree to participate will be asked to sign an informed consent form. Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations. TRIAL REGISTRATION NUMBER NCT02763956. PROTOCOL VERSION 7.1, 18 November 2020

Capacity development in food composition database management and nutritional research and education in Central and Eastern European, Middle Eastern and North African countries

Background/Objectives: Capacity development (CD) in food and nutrition is much more than formal training and includes human resource development, and organisational, institutional and legal framework development with the aim of enhancing nutrition-relevant knowledge and skills to support infrastructural development. The goal of the European Food Information Resource (EuroFIR) Network of Excellence has been to develop and integrate food composition data throughout Europe. EuroFIR joined forces in CD with the United Nations (UN) University and UN System Standing Committee on Nutrition, the Network for Capacity Development in Nutrition in Central and Eastern Europe, the Central and Eastern European Countries Food Data Systems network and with the Middle East and North African Capacity Building Initiative. The aim of this paper is to discuss an inventory of the status of food composition databases (FCDBs) and the training needs of compilers in non-EuroFIR countries in Central and Eastern Europe (CEE) and in the Middle East and North Africa (MENA), and to present the CD achieved through EuroFIR and other network collaborations. Subjects/Methods: Two online questionnaires were created addressing the FCDB status and specific training needs in countries of the targeted regions. Data were collected during 2006-2008 and then analysed. Subsequently, CD activities were organised. Results: Contacts were established in 19 CEE and 7 MENA countries, of which several had national food composition tables, but no electronic versions. Education, training, workshops, networking and the sharing of experiences were uniformly requested. Subsequently, CD activities in EuroFIR were organised focussing on food composition courses, exchange visits, workshops and individual training for PhD students, junior scientists and other staff categories, as well as conferences linked to food composition research and food information. To facilitate CD activities, EuroFIR has signed a Memorandum of Understanding with the Czech Republic, Hungary, Slovenia, Croatia and Estonia. Conclusions: EuroFIR has created training activities that complement national activities. Collaboration with other networks has provided an overview of FCDB status and training needs, providing directions for CD activities in those countries. This provides a platform for new funding and further development and networking for CD, which would be conducive to European Commission objectives and public health strategies for CD. European Journal of Clinical Nutrition (2010) 64, S134-S138; doi:10.1038/ejcn.2010.22

Quercetin prevents progression of disease in elastase/LPS-exposed mice by negatively regulating MMP expression

Abstract Background Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, emphysema and irreversible airflow limitation. These changes are thought to be due to oxidative stress and an imbalance of proteases and antiproteases. Quercetin, a plant flavonoid, is a potent antioxidant and anti-inflammatory agent. We hypothesized that quercetin reduces lung inflammation and improves lung function in elastase/lipopolysaccharide (LPS)-exposed mice which show typical features of COPD, including airways inflammation, goblet cell metaplasia, and emphysema. Methods Mice treated with elastase and LPS once a week for 4 weeks were subsequently administered 0.5 mg of quercetin dihydrate or 50% propylene glycol (vehicle) by gavage for 10 days. Lungs were examined for elastance, oxidative stress, inflammation, and matrix metalloproteinase (MMP) activity. Effects of quercetin on MMP transcription and activity were examined in LPS-exposed murine macrophages. Results Quercetin-treated, elastase/LPS-exposed mice showed improved elastic recoil and decreased alveolar chord length compared to vehicle-treated controls. Quercetin-treated mice showed decreased levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation caused by oxidative stress. Quercetin also reduced lung inflammation, goblet cell metaplasia, and mRNA expression of pro-inflammatory cytokines and muc5AC. Quercetin treatment decreased the expression and activity of MMP9 and MMP12 in vivo and in vitro, while increasing expression of the histone deacetylase Sirt-1 and suppressing MMP promoter H4 acetylation. Finally, co-treatment with the Sirt-1 inhibitor sirtinol blocked the effects of quercetin on the lung phenotype. Conclusions Quercetin prevents progression of emphysema in elastase/LPS-treated mice by reducing oxidative stress, lung inflammation and expression of MMP9 and MMP12.http://deepblue.lib.umich.edu/bitstream/2027.42/78260/1/1465-9921-11-131.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78260/2/1465-9921-11-131.pdfPeer Reviewe

Precise microwave characterization of MgO substrates for HTS circuits with superconducting post dielectric resonator

Accurate data of complex permittivity of dielectric substrates are needed for efficient design of HTS microwave planar circuits. We have tested MgO substrates from three different manufacturing batches using a dielectric resonator with superconducting parts recently developed for precise microwave characterization of laminar dielectrics at cryogenic temperatures. The measurement fixture has been fabricated using a SrLaAlO3 post dielectric resonator with DyBa2Cu3O7 end plates and silver-plated copper sidewalls to achieve the resolution of loss tangent measurements of 2 {\times} 10-6. The tested MgO substrates exhibited the average relative permittivity of 9.63 and tan {\delta} from 3.7 {\times} 10-7 to 2 {\times} 10-5 at frequency of 10.5 GHz in the temperature range from 14 to 80 K.Comment: 6 pages, 8 figures, 3 table