49 results on '"Eras J"'
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2. Use of Crude Glycerol from Biodiesel Producers and Fatty Materials to Prepare Allyl Esters
- Author
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Escribà, M., Eras, J., Villorbina, G., Balcells, M., Blanch, C., Barniol, N., and Canela, R.
- Published
- 2011
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3. The impact of various cycling regimens on phosphorus removal in chronic peritoneal dialysis patients
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JUERGENSEN, P., ERAS, J., McCLURE, B., KLIGER, A. S., and FINKELSTEIN, F. O.
- Published
- 2005
4. Productive, Distributive, Dynamic, and Allocative Efficiency Improvement Model in Colombian Public Universities.
- Author
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Arenas-Valencia, W. and Cabello-Eras, J. J.
- Subjects
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PUBLIC universities & colleges , *DATA envelopment analysis , *STRUCTURAL equation modeling , *PRINCIPAL components analysis , *BALANCED scorecard - Abstract
The measurement of efficiency in public universities has been a topic of interest for researchers and state officials in Colombia; this article presents a model that transcends the view of productive efficiency, and expands it by including aspects of equity with distributive efficiency, of acceptance by society in the allocative efficiency, and finally with the dynamic efficiency includes the time variable, with which the state can measure the stability of the indicators of interest. For the design of the model, multivariate statistical techniques and non-parametric techniques were used, such as Structural Equation Models, Principal Component Analysis, Data Envelopment Analysis, and the Balanced Scorecard. Different ranks are obtained with which university improvement plans were identified, emphasizing public institutions with high quality accreditation. A Balanced Scorecard is proposed with the indicators extracted from the sector databases that met the conditions of the techniques used. This technique suggests a causal relationship between the indicators of distributive, productive, and allocative efficiencies, where the perspective of inclusion forms the basis of the scorecard, affecting the perspective of education and research and the latter influencing the perspective of impact. Finally, it is concluded that the public university sector has great challenges in terms of inclusion and measurement of the satisfaction of society, as well as showing improvement trends in the measured aspects as reflected in the DEA Malmquist index. As a result, a model is obtained for university administrators to identify the aspects in which they must invest the public budget that guarantees the greater multidimensional efficiency of Colombian public universities. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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5. Prevalence of pesticides in postconsumer agrochemical polymeric packaging.
- Author
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Eras, J., Costa, J., Vilaró, F., Pelacho, A.M., Canela-Garayoa, R., and Martin-Closas, L.
- Subjects
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AGRICULTURAL chemicals , *PACKAGING waste , *PHYSIOLOGICAL effects of pesticides , *FEEDSTOCK , *SOLVENTS - Abstract
Pesticide remains contained in agrochemical packaging waste are a source of uncontrolled risk for human health; they are also a quality feedstock for the plastic recycling industry. Many governments have recently started to establish laws and regulations to develop systems for recovering and recycling the polymeric packages used for pesticides. There is also a demand in having a procedure to control the suitability of the pesticide packages to be reused. We have developed a two-step operation process to assess the pesticide residues in agricultural containers made of a variety of polymeric matrices. The procedure is based on an extraction with a solvent mixture followed by UPLC-MS/MS determination. Solvents for neutral pesticides were selected considering the Hildebrand solubility (δ) of solvents and polymers together with those estimated for the pesticides. The proposed technique is effective in recovering imbibed pesticides in polymeric matrices. Also, a simplified extraction procedure has been tested to become a routine method for these wastes. We have found that in many cases a significant amount of pesticides remain into the polymeric matrix, even after a standardized cleaning; the impact of releasing these hazardous compounds into the environment is to be of further consideration. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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6. Entrapment in polymeric material of resting cells of Aspergillus flavus with lipase activity. Application to the synthesis of ethyl laurate.
- Author
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Yara-Varón, E., Eras, J., Torres, M., Villorbina, G., Espart, A., and Canela-Garayoa, R.
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- 2014
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7. Note. Chlorotrimethylsilane—A Reagent for the Direct Analysis of Fats and Oils in Solid and Paste Samples.
- Author
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Eras, J., Dolcet, A., Ferran, J., and Canela, R.
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FATTY acids , *ESTERS , *OLIVE , *SUNFLOWER seeds , *HAZELNUTS , *MAYONNAISE , *SAUSAGES - Abstract
Fatty acid pentyl esters (FAPEs) from eight solid and pasted samples of various substances—olives, sunflower seeds, semiroasted hazelnuts, infant milk powder, mayonnaise sauce, sausage, muesli and cheese—were directly prepared using chlorotrimethylsilane (CTMS) and pentanol. The pentyl esters were analysed by GLC and the relative percentages were compared with those obtained applying the CTMS method to the oil extracted from the samples. Although significant differences in individual fatty acid compositions were observed in some cases, those differences were randomly distributed. Moreover, applying the minimum least square regression method the two sets of results might be considered statistically equivalent. Thus, calculated slope and intercept did not differ significantly from 1 and 0. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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8. Abortion and its effect on risk of preeclampsia and transient hypertension.
- Author
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Eras, Jennifer L., Saftlas, Audrey F., Triche, Elizabeth, Hsu, Chaur-Dong, Risch, Harvey A., Bracken, Michael B., Eras, J L, Saftlas, A F, Triche, E, Hsu, C D, Risch, H A, and Bracken, M B
- Published
- 2000
9. Compounds released from unused biodegradable mulch materials after contact with water.
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Serrano-Ruíz, H., Eras, J., Martín-Closas, L., and Pelacho, A.M.
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BIODEGRADABLE materials , *BIODEGRADABLE plastics , *PLASTIC mulching , *ADIPIC acid , *TEREPHTHALIC acid , *DRUG disposal , *3-Hydroxybutyric acid , *POLYLACTIC acid - Abstract
Biodegradable plastics (BDP) are an alternative to environmental and economical drawbacks of PE agricultural mulches. They are intended to biodegrade into the soil or in compost. BDP materials certified as biodegradable in soil or in compost have passed ecotoxicity biotests after biodegradation, but most BDP ecotoxicity studies do not provide insights on the components these materials may release. The present work aims to characterize the compounds released from BDP to water solutions before biodegradation. New unused BDP, one paper mulch for agricultural use, a control without any material, and one non-degradable PE mulch, were incubated in a water solution for identification of the released compounds through GC-MS, NMR and UPLC-MS/MS. All BDP released compounds and modified the pH of the solution, with differences depending on the composition of the material. A diversity of compounds used in the formulation of the materials, and their derivatives, were identified in most solutions; mostly, but not exclusively, adipic acid, 1,4-butanediol, lactic acid, glycerol, terephthalic acid, mono and disaccharides, or fatty acids; some were also quantified. Results prove BDP to interact with the environment and to release compounds well before biodegradation may be acknowledged. They are also a step forward towards identifying the links between reported changes in plant development and specific compounds or compound mixtures, and towards a more sustainable and targeted selection and use of BDP for mulching specific plant species in agriculture. • Biodegradable plastic mulches release compounds in water before biodegradation in soil. • PBAT, PLA and PHB in blends of biodegradable mulches undergo partial hydrolysis and release soluble compounds into water. • Concentration of released compounds from PBAT, PLA and PHB are low. • Released compounds concentrations do not suggest ecotoxicity of single compounds; regardless effects of extracts on plants. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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10. Reactivity of thienopyrroles. Synthesis of isomeric nitro and bromothienopyrroles.
- Author
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Eras, J., Gálvez, C., and Garct́a, F.
- Published
- 1984
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11. A simple and fast method for metabolomic analysis by gas liquid chromatography-mass spectrometry.
- Author
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Cosovanu D, Llovera M, Villorbina G, Canela-Garayoa R, and Eras J
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- Aldehydes analysis, Bacteria, Carbohydrates analysis, Fatty Acids analysis, Fatty Alcohols analysis, Fungi, Humans, Hydrocarbons analysis, Hydroxybenzoates analysis, Mass Spectrometry, Metabolome, Methanol, Olea chemistry, Plant Leaves chemistry, Plants, Pyridines, Sebum chemistry, Sterols analysis, Terpenes analysis, Trimethylsilyl Compounds, Vaccinium myrtillus chemistry, Gas Chromatography-Mass Spectrometry methods, Metabolomics methods
- Abstract
Introduction: The metabolomic profile is an essential tool for understanding the physiological processes of biological samples and their changes. In addition, it makes it possible to find new substances with industrial applications or use as drugs. As GC-MS is a very common tool for obtaining the metabolomic profile, a simple and fast method for sample preparation is required., Objectives: The aim of this research was to develop a direct derivatization method for GC-MS to simplify the sample preparation process and apply it to a wide range of samples for non-targeted metabolomic analysis purposes., Methods: One pot combined esterification of carboxylic acids with methanol and silylation of the hydroxyl groups was achieved using a molar excess of chlorotrimethylsilane with respect to methanol in the presence of pyridine., Results: The metabolome profile obtained from different samples, such as bilberry and cherry cuticles, olive leaves, P. aeruginosa and E. coli bacteria, A. niger fungi and human sebum from the ceruminous gland, shows that the procedure allows the identification of a wide variety of metabolites. Aliphatic fatty acids, hydroxyfatty acids, phenolic and other aromatic compounds, fatty alcohols, fatty aldehydes dimethylacetals, hydrocarbons, terpenoids, sterols and carbohydrates were identified at different MSI levels using their mass spectra., Conclusion: The metabolomic profile of different biological samples can be easily obtained by GC-MS using an efficient simultaneous esterification-silylation reaction. The derivatization method can be carried out in a short time in the same injection vial with a small amount of reagents.
- Published
- 2021
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12. Architecture and function of human uromodulin filaments in urinary tract infections.
- Author
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Weiss GL, Stanisich JJ, Sauer MM, Lin CW, Eras J, Zyla DS, Trück J, Devuyst O, Aebi M, Pilhofer M, and Glockshuber R
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- Adhesins, Bacterial chemistry, Cryoelectron Microscopy, Glycosylation, Humans, Ligands, Urinary Tract Infections metabolism, Uromodulin chemistry, Uromodulin physiology
- Abstract
Uromodulin is the most abundant protein in human urine, and it forms filaments that antagonize the adhesion of uropathogens; however, the filament structure and mechanism of protection remain poorly understood. We used cryo-electron tomography to show that the uromodulin filament consists of a zigzag-shaped backbone with laterally protruding arms. N-glycosylation mapping and biophysical assays revealed that uromodulin acts as a multivalent ligand for the bacterial type 1 pilus adhesin, presenting specific epitopes on the regularly spaced arms. Imaging of uromodulin-uropathogen interactions in vitro and in patient urine showed that uromodulin filaments associate with uropathogens and mediate bacterial aggregation, which likely prevents adhesion and allows clearance by micturition. These results provide a framework for understanding uromodulin in urinary tract infections and in its more enigmatic roles in physiology and disease., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
- Published
- 2020
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13. Rice-Associated Rhizobacteria as a Source of Secondary Metabolites against Burkholderia glumae .
- Author
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Peñaloza Atuesta GC, Murillo Arango W, Eras J, Oliveros DF, and Méndez Arteaga JJ
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- Acetates chemistry, Enterobacter classification, Fermentation, Gas Chromatography-Mass Spectrometry, Magnetic Resonance Spectroscopy, Metabolomics, Phenylpropionates chemistry, Phosphates chemistry, Phylogeny, RNA, Ribosomal, 16S genetics, Secondary Metabolism, Spectroscopy, Fourier Transform Infrared, Virulence genetics, Anti-Bacterial Agents pharmacology, Burkholderia pathogenicity, Enterobacter metabolism, Oryza microbiology, Plant Diseases microbiology, Plant Diseases prevention & control
- Abstract
Various diseases, including bacterial panicle blight (BPB) and sheath rot, threaten rice production. It has been established that Burkholderia glumae ( B. glumae ) is the causative agent of the above mentioned pathologies. In the present study, antagonistic activity, growth promotion, and the metabolite profiles of two rhizobacteria, isolated in different paddy fields, were assessed against B. glumae . Strains were identified based on 16S rRNA gene sequences, and the phylogenetic analyses showed that both strains belong to the genus Enterobacter , with high similarity to the strain Enterobacter tabaci NR146667.2 (99%). The antagonistic activity was assessed with the disc diffusion method. Active fractions were isolated through a liquid/liquid extraction with ethyl acetate (EtOAc) from the fermentation media, and their antibacterial activities were evaluated following the Clinical and Laboratory Standards Institute (CLSI) guidelines. The Pikovskaya modified medium was used to test the ability of in vitro inorganic phosphorus solubilization, and BSB1 proved to be the best inorganic phosphorus solubilizer, with a solubilization index (SI) of 4.5 ± 0.2. The glass-column fractionation of the EtOAc extracted from BCB11 produced an active fraction (25.9 mg) that inhibited the growth of five B. glumae strains by 85-95%. Further, metabolomic analysis, based on GC-MS, showed 3-phenylpropanoic acid (3-PPA) to be the main compound both in this fraction (46.7%), and in the BSB1 extract (28.6%). This compound showed antibacterial activity against all five strains of B. glumae with a minimum inhibitory concentration (MIC) of 1000 mg/L towards all of them. The results showed that rice rhizosphere microorganisms are a source of compounds that inhibit B. glumae growth and are promising plant growth promoters (PGP).
- Published
- 2020
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14. Combined Analysis of Primary Metabolites and Phenolic Compounds to Authenticate Commercial Monovarietal Peach Purees and Pear Juices.
- Author
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Delpino-Rius A, Eras J, Gatius F, Balcells M, and Canela-Garayoa R
- Subjects
- Chromatography, Liquid, Fruit chemistry, Fruit and Vegetable Juices analysis, Phenols isolation & purification, Principal Component Analysis, Tandem Mass Spectrometry, Phenols chemistry, Prunus persica chemistry, Pyrus chemistry
- Abstract
Here we authenticated single-varietal peach purees and pear juices on the basis of primary metabolite and phenolic compound analysis by Proton Nuclear Magnetic Resonance (
1 H-NMR) and Ultra Performance Liquid Chromatography coupled to Photodiode Array and Tandem Mass Spectrometry (UPLC-PDA-MS/MS), respectively. After suitable preprocessing, the1 H-NMR and chromatographic data were evaluated by principal component analysis (PCA). The PCA combining data from primary metabolites and phenolic compounds allowed the separation of the clusters in all cases, allowing discrimination of processed and unprocessed peach purees, both separately and pooled. The PCA of primary metabolites allowed the cluster separation of purees of distinct peach varieties but not between processed and non-processed purees. The PCA of phenolic compounds allowed better cluster separation than of primary metabolites. For pear juices, both PCA approaches allowed satisfactory discrimination of Alejandrina, Conference, and Blanquilla cultivars. These approaches may help to better control cultivar authenticity in fruit products. It could therefore contribute to the development of a process to achieve products characterized by a quality characteristic of a given cultivar.- Published
- 2019
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15. Chemical Characterization and Biotechnological Applicability of Pigments Isolated from Antarctic Bacteria.
- Author
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Silva TR, Tavares RSN, Canela-Garayoa R, Eras J, Rodrigues MVN, Neri-Numa IA, Pastore GM, Rosa LH, Schultz JAA, Debonsi HM, Cordeiro LRG, and Oliveira VM
- Subjects
- Antarctic Regions, Carotenoids chemistry, Carotenoids isolation & purification, Industrial Microbiology, Pigments, Biological isolation & purification, Arthrobacter chemistry, Biotechnology, Flavobacteriaceae chemistry, Pigments, Biological chemistry
- Abstract
Considering the global trend in the search for alternative natural compounds with antioxidant and sun protection factor (SPF) boosting properties, bacterial carotenoids represent an opportunity for exploring pigments of natural origin which possess high antioxidant activity, lower toxicity, no residues, and no environmental risk and are readily decomposable. In this work, three pigmented bacteria from the Antarctic continent, named Arthrobacter agilis 50cyt, Zobellia laminarie 465, and Arthrobacter psychrochitiniphilus 366, were able to withstand UV-B and UV-C radiation. The pigments were extracted and tested for UV absorption, antioxidant capacity, photostability, and phototoxicity profile in murine fibroblasts (3T3 NRU PT-OECD TG 432) to evaluate their further potential use as UV filters. Furthermore, the pigments were identified by ultra-high-performance liquid chromatography-photodiode array detector-mass spectrometry (UPLC-PDA-MS/MS). The results showed that all pigments presented a very high antioxidant activity and good stability under exposure to UV light. However, except for a fraction of the A. agilis 50cyt pigment, they were shown to be phototoxic. A total of 18 different carotenoids were identified from 23 that were separated on a C18 column. The C50 carotenes bacterioruberin and decaprenoxanthin (including its variations) were confirmed for A. agilis 50cyt and A. psychrochitiniphilus 366, respectively. All-trans-bacterioruberin was identified as the pigment that did not express phototoxic activity in the 3T3 NRU PT assay (MPE < 0.1). Zeaxanthin, β-cryptoxanthin, β-carotene, and phytoene were detected in Z. laminarie 465. In conclusion, carotenoids identified in this work from Antarctic bacteria open perspectives for their further biotechnological application towards a more sustainable and environmentally friendly way of pigment exploitation.
- Published
- 2019
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16. Pigments in an iridescent bacterium, Cellulophaga fucicola, isolated from Antarctica.
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Silva TR, Canela-Garayoa R, Eras J, Rodrigues MVN, Dos Santos FN, Eberlin MN, Neri-Numa IA, Pastore GM, Tavares RSN, Debonsi HM, Cordeiro LRG, Rosa LH, and Oliveira VM
- Subjects
- Animals, Antarctic Regions, Antioxidants chemistry, Antioxidants isolation & purification, Antioxidants pharmacology, Carotenoids chemistry, Carotenoids isolation & purification, Carotenoids pharmacology, Cell Line, Chromatography, High Pressure Liquid, Fibroblasts drug effects, Fibroblasts metabolism, Flavobacteriaceae radiation effects, Mass Spectrometry, Mice, Pigments, Biological chemistry, Pigments, Biological isolation & purification, Pigments, Biological pharmacology, Ultraviolet Rays, Antioxidants analysis, Carotenoids analysis, Flavobacteriaceae chemistry, Flavobacteriaceae isolation & purification, Pigments, Biological analysis
- Abstract
An iridescent yellow pigmented bacterium isolated from the Antarctic continent, named Cellulophaga fucicola strain 416, was found to be able to tolerate UV-B radiation. Its crude pigment extract was tested for antioxidant capacity, UV light stability and phototoxicity profile against murine fibroblast lines. The pigments were further isolated and chemically identified by ultra-high-performance liquid chromatography with photodiode array and mass spectrometry detectors. The results showed that the pigment extract presented weak stability under exposure to UV light, a phototoxic profile in the 3t3 Neutral Red Uptake test and a very high antioxidant activity, suggesting that it could be used as food and feed colourants. Zeaxanthin and two isomers of zeaxanthin, β-cryptoxanthin and β-carotene, were identified using a C18 column. These five carotenoids were the major pigments isolated from C. fucicola 416. In conclusion, the identification of pigments produced by the bacterial strain under study may help us understand how bacteria thrive in high UV and cold environments, and opens avenues for further biotechnological application towards a more sustainable and environmentally friendly way of pigment exploitation.
- Published
- 2019
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17. Elongation of the Hydrophobic Chain as a Molecular Switch: Discovery of Capsaicin Derivatives and Endogenous Lipids as Potent Transient Receptor Potential Vanilloid Channel 2 Antagonists.
- Author
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Schiano Moriello A, López Chinarro S, Novo Fernández O, Eras J, Amodeo P, Canela-Garayoa R, Vitale RM, Di Marzo V, and De Petrocellis L
- Subjects
- Animals, HEK293 Cells, Humans, Ligands, Lipids chemistry, Models, Molecular, Molecular Structure, Protein Conformation, Rats, Structure-Activity Relationship, Capsaicin chemistry, Drug Discovery, Hydrophobic and Hydrophilic Interactions, Lipids pharmacology, TRPV Cation Channels antagonists & inhibitors
- Abstract
The transient receptor potential vanilloid type-2 (TRPV2) protein is a nonselective Ca
2+ permeable channel member of the TRPV subfamily, still considered an orphan TRP channel due to the scarcity of available selective and potent pharmacological tools and endogenous modulators. Here we describe the discovery of novel synthetic long-chain capsaicin derivatives as potent TRPV2 antagonists in comparison to the totally inactive capsaicin, the role of their hydrophobic chain, and how the structure-activity relationships of such derivatives led, through a ligand-based approach, to the identification of endogenous long-chain fatty acid ethanolamides or primary amides acting as TRPV2 antagonists. Both synthetic and endogenous antagonists exhibited differential inhibition against known TRPV2 agonists characterized by distinct kinetic profiles. These findings represent the first example of both synthetic and naturally occurring TRPV2 modulators with efficacy in the submicromolar/low-micromolar range, which will be useful for clarifying the physiopathological roles of this receptor, its regulation, and its targeting in pathological conditions.- Published
- 2018
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18. A fast and reliable ultrahigh-performance liquid chromatography method to assess the fate of chlorophylls in teas and processed vegetable foodstuff.
- Author
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Delpino-Rius A, Cosovanu D, Eras J, Vilaró F, Balcells M, and Canela-Garayoa R
- Subjects
- Chlorophyll chemistry, Fruit chemistry, Mass Spectrometry methods, Reproducibility of Results, Chlorophyll analysis, Chromatography, High Pressure Liquid, Food Analysis methods, Plant Preparations chemistry, Tea chemistry, Vegetables chemistry
- Abstract
A total of 48 chlorophylls and derivatives were identified and successfully determined in tea and processed vegetable and fruit foodstuff by UHPLC with photodiode-array and mass spectrometry detection. The method allowed the proper separation of chlorophyll derivatives resulting from demetallation, dephytilation, decarbomethoxylation, epimerisation and copperisation. The method was performed in less than 12 min, using an optimised ternary gradient (MeOH, iPrOH, MeCN and H
2 O with 10 mM of ammonium acetate) on an ACQUITY HSS T3 column. Mass spectrometry, applying both ESI and APCI ionization sources, was used for identification purposes. The method was applied to evaluate the degree of processing in teas of different origin and quality. It allowed differentiation between supermarket own-brand tea bags and teas sold by specialised shops. Pheophytins, pheophorbides and pyro derivatives were found mainly in processed green vegetable and fruit products thereof. However, chlorophyll-derived food colorants, such as Cu-chlorophyllins, Cu-pheophytins, Cu-pyropheophytins, Cu-pheophorbides and Cu-pyropheophorbides, were also detected in several products., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
- Full Text
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19. Bulk industrial fruit fibres. Characterization and prevalence of the original fruit metabolites.
- Author
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Delpino-Rius A, Marsol-Vall A, Eras J, Llovera M, Cubero MÁ, Balcells M, and Canela-Garayoa R
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- Carotenoids analysis, Carotenoids chemical synthesis, Carotenoids metabolism, Citrus chemistry, Citrus metabolism, Citrus sinensis chemistry, Citrus sinensis metabolism, Daucus carota chemistry, Daucus carota metabolism, Malus chemistry, Malus metabolism, Oleanolic Acid analysis, Oleanolic Acid chemistry, Oleanolic Acid metabolism, Prunus persica chemistry, Prunus persica metabolism, Pyrus chemistry, Pyrus metabolism, Sugars analysis, Sugars chemistry, Sugars metabolism, Triterpenes analysis, Triterpenes chemistry, Triterpenes metabolism, Ursolic Acid, Food Industry, Fruit chemistry, Fruit metabolism, Fruit and Vegetable Juices analysis
- Abstract
Here we analysed the content of primary and secondary metabolites in nine types of industrially processed fibres derived from the juice industry. Specifically, we examined fibre from: apple, peach, and pear, as non-citrus fruits; the peel and flesh of orange and tangerine, and lemon flesh, as citrus fruits; and carrot, as vegetable. Regarding primary metabolites, the sugar content ranged from 21.6 mg/g in lemon to 290 mg/g in orange peel and lower mass organic acid content ranged from 25.0 mg/g in pear to 250 mg/g in lemon. The content of fatty acids were constant during fibre processing, ranging from 0.5 to 1.46%. Furthermore, the fatty acid profile was not affect for the processing. Concerning secondary metabolites, industrial processing did not decrease the sterols content, which ranged from 0.51 to 1.66 μg/g. Regarding carotenoids, of note was the presence of epoxycarotenoids, which may reflect the quality of the industrial process, thus giving added value to the by-product., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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20. Development of a SBSE-TD method coupled to GC-MS and chemometrics for the differentiation of variety and processing conditions in peach juices.
- Author
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Marsol-Vall A, Balcells M, Eras J, and Canela-Garayoa R
- Subjects
- 4-Butyrolactone analogs & derivatives, Fruit and Vegetable Juices, Gas Chromatography-Mass Spectrometry, Lactones, Reproducibility of Results, Prunus persica
- Abstract
Peach juices of distinct varieties, namely yellow- and red-fleshed, and commercial and freshly blended were analyzed. The method used was based on Stir Bar Sorptive Extraction (SBSE) involving a polydimethylsiloxane-coated stir bar with thermal desorption (TD), followed by gas chromatography coupled to mass spectrometry (GC-MS) analysis. The resulting analytical data included 41 compounds belonging to several chemical classes, such as aldehydes, alcohols, lactones, terpenoids, fatty aldehydes, fatty acids and hydrocarbons. Furthermore, chemometric data treatment using unsupervised analysis (PCA) proved useful to classify peach juices on the basis of variety. Stepwise Linear Discriminant Analysis (SLDA) showed that a reduced number of variables (14 compounds), including lactones (6-pentyl-α-pyrone, γ-decalactone, γ-dodecalactone, and δ-dodecalactone), fatty acids (hexadecanoic acid), fatty aldehydes (tetracosanal and octacosanal), hydrocarbons (C23, C26, C27, C29, and C33), and alcohols (phytol and α-tocopherol), were necessary to classify the juice samples according to variety and processing conditions., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
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21. Determinants of the assembly and function of antibody variable domains.
- Author
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Herold EM, John C, Weber B, Kremser S, Eras J, Berner C, Deubler S, Zacharias M, and Buchner J
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- Antibodies, Monoclonal chemistry, Antibodies, Monoclonal genetics, Antibodies, Monoclonal metabolism, DNA Mutational Analysis, Humans, Immunoglobulin Variable Region chemistry, Immunoglobulin Variable Region metabolism, Protein Binding, Protein Stability, Immunoglobulin Variable Region genetics, Recombination, Genetic
- Abstract
The antibody Fv module which binds antigen consists of the variable domains V
L and VH . These exhibit a conserved ß-sheet structure and comprise highly variable loops (CDRs). Little is known about the contributions of the framework residues and CDRs to their association. We exchanged conserved interface residues as well as CDR loops and tested the effects on two Fvs interacting with moderate affinities (KD s of ~2.5 µM and ~6 µM). While for the rather instable domains, almost all mutations had a negative effect, the more stable domains tolerated a number of mutations of conserved interface residues. Of particular importance for Fv association are VL P44 and VH L45. In general, the exchange of conserved residues in the VL /VH interface did not have uniform effects on domain stability. Furthermore, the effects on association and antigen binding do not strictly correlate. In addition to the interface, the CDRs modulate the variable domain framework to a significant extent as shown by swap experiments. Our study reveals a complex interplay of domain stability, association and antigen binding including an unexpected strong mutual influence of the domain framework and the CDRs on stability/association on the one side and antigen binding on the other side.- Published
- 2017
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22. Dispersive liquid-liquid microextraction and injection-port derivatization for the determination of free lipophilic compounds in fruit juices by gas chromatography-mass spectrometry.
- Author
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Marsol-Vall A, Balcells M, Eras J, and Canela-Garayoa R
- Subjects
- Acetamides chemistry, Fatty Acids analysis, Fatty Acids isolation & purification, Fluoroacetates chemistry, Limit of Detection, Liquid Phase Microextraction, Phytosterols analysis, Phytosterols isolation & purification, Pyridines chemistry, Trimethylsilyl Compounds chemistry, Triterpenes analysis, Triterpenes isolation & purification, Fruit and Vegetable Juices analysis, Gas Chromatography-Mass Spectrometry
- Abstract
A method consisting of dispersive liquid-liquid microextraction (DLLME) followed by injection-port derivatization and gas chromatography-mass spectrometry (GC-MS) for the analysis of free lipophilic compounds in fruit juices is described. The method allows the analysis of several classes of lipophilic compounds, such as fatty acids, fatty alcohols, phytosterols and triterpenes. The chromatographic separation of the compounds was achieved in a chromatographic run of 25.5min. The best conditions for the dispersive liquid-liquid microextraction were 100μL of CHCl
3 in 1mL of acetone. For the injection-port derivatization, the best conditions were at 280°C, 1min purge-off, and a 1:1 sample:derivatization reagent ratio (v/v) using N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA):pyridine (1:1) as reagent. Quality parameters were assessed for the target compounds, giving a limits of detection (LODs) ranging from 1.1 to 5.7ng/mL and limits of quantification (LOQs) from 3.4 to 18.7ng/mL for linoleic and stearic acid, respectively. Repeatability (%RSD, n=5) was below 11.51% in all cases. In addition, the method linearity presented an r2 ≥0.990 for all ranges applied. Finally, the method was used to test the lipophilic fraction of various samples of commercial fruit juice., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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23. Accelerating the Association of the Most Stable Protein-Ligand Complex by More than Two Orders of Magnitude.
- Author
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Giese C, Eras J, Kern A, Schärer MA, Capitani G, and Glockshuber R
- Subjects
- Ligands, Models, Molecular, Protein Engineering, Static Electricity, Surface Properties, Escherichia coli Proteins chemistry, Fimbriae Proteins chemistry
- Abstract
The complex between the bacterial type 1 pilus subunit FimG and the peptide corresponding to the N-terminal extension (termed donor strand, Ds) of the partner subunit FimF (DsF) shows the strongest reported noncovalent molecular interaction, with a dissociation constant (KD ) of 1.5×10(-20) m. However, the complex only exhibits a slow association rate of 330 m(-1) s(-1) that limits technical applications, such as its use in affinity purification. Herein, a structure-based approach was used to design pairs of FimGt (a FimG variant lacking its own N-terminal extension) and DsF variants with enhanced electrostatic surface complementarity. Association of the best mutant FimGt/DsF pairs was accelerated by more than two orders of magnitude, while the dissociation rates and 3D structures of the improved complexes remained essentially unperturbed. A KD value of 8.8×10(-22) m was obtained for the best mutant complex, which is the lowest value reported to date for a protein/ligand complex., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
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24. Injection-port derivatization coupled to GC-MS/MS for the analysis of glycosylated and non-glycosylated polyphenols in fruit samples.
- Author
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Marsol-Vall A, Balcells M, Eras J, and Canela-Garayoa R
- Subjects
- Acetamides chemistry, Fluoroacetates chemistry, Glycosylation, Limit of Detection, Solid Phase Extraction methods, Temperature, Trimethylsilyl Compounds chemistry, Fruit chemistry, Gas Chromatography-Mass Spectrometry methods, Polyphenols analysis, Tandem Mass Spectrometry methods
- Abstract
Polyphenols, including glycosylated polyphenols, were analyzed via a procedure based on injection-port derivatization coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS). The polyphenols in lyophilized fruit samples were extracted with an acidified MeOH mixture assisted by ultrasound. Samples were dried under vacuum, and carbonyl groups were protected with methoxylamine. Free hydroxyl groups were subsequently silylated in-port. Mass fragmentations of 17 polyphenol and glycosylated polyphenol standards were examined using Multiple Reaction Monitoring (MRM) as the acquisition mode. Furthermore, in-port derivatization was optimized in terms of optimal injection port temperature, derivatization time and sample: N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) volume ratio. A C18 solid-phase-extraction clean-up method was used to reduce matrix effects and injection liner degradation. Using this clean-up method, recoveries for samples spiked at 1 and 10μg/g ranged from 52% to 98%, depending on the chemical compound. Finally, the method was applied to real fruit samples containing the target compounds. The complete chromatographic runtime was 15min, which is faster than reported for recent HPLC methods able to analyze similar compounds., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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25. A rapid gas chromatographic injection-port derivatization method for the tandem mass spectrometric determination of patulin and 5-hydroxymethylfurfural in fruit juices.
- Author
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Marsol-Vall A, Balcells M, Eras J, and Canela-Garayoa R
- Subjects
- Furaldehyde analysis, Malus chemistry, Pyrus chemistry, Fruit and Vegetable Juices analysis, Furaldehyde analogs & derivatives, Gas Chromatography-Mass Spectrometry methods, Patulin analysis, Tandem Mass Spectrometry methods
- Abstract
A novel method consisting of injection-port derivatization coupled to gas chromatography-tandem mass spectrometry is described. The method allows the rapid assessment of 5-hydroxymethylfurfural (HMF) and patulin content in apple and pear derivatives. The chromatographic separation of the compounds was achieved in a short chromatographic run (12.2min) suitable for routine controls of these compounds in the fruit juice industry. The optimal conditions for the injection-port derivatization were at 270°C, 0.5min purge-off, and a 1:2 sample:derivatization reagent ratio (v/v). These conditions represent an important saving in terms of derivatization reagent consumption and sample preparation time. Quality parameters were assessed for the target compounds, giving LOD of 0.7 and 1.6μg/kg and LOQ of 2 and 5μg/kg for patulin and HMF, respectively. These values are below the maximum patulin concentration in food products intended for infants and young children. Repeatability (%RSD n=5) was below 12% for both compounds. In addition, the method linearity ranged between 25 and 1000μg/kg and between 5 and 192μg/kg for HMF and patulin, respectively. Finally, the method was applied to study HMF and patulin content in various fruit juice samples., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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26. Catch-bond mechanism of the bacterial adhesin FimH.
- Author
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Sauer MM, Jakob RP, Eras J, Baday S, Eriş D, Navarra G, Bernèche S, Ernst B, Maier T, and Glockshuber R
- Subjects
- Adhesins, Escherichia coli genetics, Biomechanical Phenomena, Escherichia coli chemistry, Escherichia coli genetics, Escherichia coli Infections metabolism, Fimbriae Proteins genetics, Fimbriae, Bacterial chemistry, Fimbriae, Bacterial genetics, Fimbriae, Bacterial metabolism, Humans, Ligands, Mannose chemistry, Mannose metabolism, Molecular Dynamics Simulation, Protein Binding, Protein Structure, Tertiary, Adhesins, Escherichia coli chemistry, Adhesins, Escherichia coli metabolism, Bacterial Adhesion, Escherichia coli physiology, Escherichia coli Infections microbiology, Fimbriae Proteins chemistry, Fimbriae Proteins metabolism
- Abstract
Ligand-receptor interactions that are reinforced by mechanical stress, so-called catch-bonds, play a major role in cell-cell adhesion. They critically contribute to widespread urinary tract infections by pathogenic Escherichia coli strains. These pathogens attach to host epithelia via the adhesin FimH, a two-domain protein at the tip of type I pili recognizing terminal mannoses on epithelial glycoproteins. Here we establish peptide-complemented FimH as a model system for fimbrial FimH function. We reveal a three-state mechanism of FimH catch-bond formation based on crystal structures of all states, kinetic analysis of ligand interaction and molecular dynamics simulations. In the absence of tensile force, the FimH pilin domain allosterically accelerates spontaneous ligand dissociation from the FimH lectin domain by 100,000-fold, resulting in weak affinity. Separation of the FimH domains under stress abolishes allosteric interplay and increases the affinity of the lectin domain. Cell tracking demonstrates that rapid ligand dissociation from FimH supports motility of piliated E. coli on mannosylated surfaces in the absence of shear force.
- Published
- 2016
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27. Comprehensive Two-dimensional Gas Chromatography Time-of-flight Mass Spectrometry to Assess the Presence of α,α-Trehalose and Other Disaccharides in Apple and Peach.
- Author
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Marsol-Vall A, Balcells M, Eras J, and Canela-Garayoa R
- Subjects
- Disaccharides chemistry, Food Analysis instrumentation, Food Analysis methods, Fruit chemistry, Gas Chromatography-Mass Spectrometry instrumentation, Gas Chromatography-Mass Spectrometry standards, Limit of Detection, Disaccharides analysis, Gas Chromatography-Mass Spectrometry methods, Malus chemistry, Prunus persica chemistry, Trehalose analysis
- Abstract
Introduction: Carbohydrates are important constituents in fruits. Among the carbohydrates, disaccharides have rarely been studied in apple and peach. Indeed, the abiotic stress biomarker and preservation agent α,α-trehalose is a disaccharide., Objectives: To establish a comprehensive method based on two-dimensional gas chromatography combined with time-of-flight MS detection (GC × GC-ToF/MS) to analyse the disaccharide composition of apple and peach., Methods: The sample preparation was based on aqueous-methanolic extraction of the analytes, followed by oxime formation and trimethylsilylation of the disaccharides. First, three columns were tested with standards on the one-dimensional system. Next, to perform the sample analysis using GC × GC-MS (which offers significant advantages over conventional GC because it allows higher separation efficiencies), various column configurations were assessed on the two-dimensional system to obtain enhanced separation and low detection limits. The column sets tested included non-polar/semi-polar, semi-polar/polar and polar/non-polar., Results: Using the method that proved to be more efficient, namely the method developed with the semi-polar/non-polar configuration, ten disaccharides were identified, based on analytical standards, retention index and mass spectra. These compounds were quantified in several varieties of apple and peach fruit using the developed GC × GC method and linear curve calibration, resulting in substantial differences among the fruits. However, cultivars within the fruits exhibited no significant differences., Conclusion: The proposed method allowed for the identification and quantification of several disaccharides in apple and peach, including the biomarker α,α-trehalose., (Copyright © 2015 John Wiley & Sons, Ltd.)
- Published
- 2015
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28. Characterisation of phenolic compounds in processed fibres from the juice industry.
- Author
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Delpino-Rius A, Eras J, Vilaró F, Cubero MÁ, Balcells M, and Canela-Garayoa R
- Subjects
- Beverages analysis, Chromatography, High Pressure Liquid, Food Industry, Fruit chemistry, Fruit metabolism, Malus chemistry, Malus metabolism, Plant Extracts chemistry, Proanthocyanidins chemistry, Prunus chemistry, Prunus metabolism, Pyrus chemistry, Pyrus metabolism, Tandem Mass Spectrometry, Phenols chemistry
- Abstract
The content of phenolic compounds was determined in nine industrially processed fibres derived from the juice industry. Apple, peach, and pear as non-citrus fruit fibres were examined, as well as orange peel and flesh, tangerine peel and flesh, and lemon flesh as citrus fruit fibres, and carrot as vegetable fibre. The extractable phenolic profile of all fibres was obtained by UPLC-PDA-FLR-MS/MS. Forty phenolic compounds were identified and their concentrations determined. In addition, bound phenolic acids and proanthocyanidins were measured in solid residues in order to determine the phenolic compounds remaining. Also, to allow the comparison of the profiles and contents in the fresh fruit and fibres, we analysed extractable and bound phenolic compounds in lyophilized peel and pulp from fresh fruit. The profile and phenolic content of the fibres was similar to that of the fresh fruit, except for flavan-3-ols, which registered lower values., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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29. Ultra performance liquid chromatography analysis to study the changes in the carotenoid profile of commercial monovarietal fruit juices.
- Author
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Delpino-Rius A, Eras J, Marsol-Vall A, Vilaró F, Balcells M, and Canela-Garayoa R
- Subjects
- Chromatography, High Pressure Liquid methods, Freeze Drying, Malus, Prunus, Pyrus, Tandem Mass Spectrometry, Beverages analysis, Carotenoids analysis, Fruit chemistry
- Abstract
We have developed an analytical method that allows the simultaneous determination of epoxycarotenoids, hydroxycarotenoids and carotenes in monovarietal fresh homemade and industrially processed fruit products. Analyses were carried out using ultra performance liquid chromatography (UPLC). The extraction method was optimized using methanol as the first extraction solvent for lyophilized samples followed by a saponification step. Recoveries ranged between 75% and 104% depending on the compound. Repeatability was better than 10% for all compounds (%RSD, n=3). The chromatographic analysis takes less than 17min. In this short period, up to 27 carotenoids were identified in apple, peach and pear products. The developed method allowed us to differentiate juice from six varieties of apple by their carotenoid profile. Moreover, the methodology allows us to differentiate the carotenoid profiles from commercial juices and homemade fresh peach and pear juices, as well as to study the rearrangements of 5,6- to 5,8-epoxycarotenoids., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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30. Resistance to peloruside A and laulimalide: functional significance of acquired βI-tubulin mutations at sites important for drug-tubulin binding.
- Author
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Kanakkanthara A, Eras J, Northcote PT, Cabral F, and Miller JH
- Subjects
- Antineoplastic Agents pharmacology, Cell Line, Tumor, Cell Proliferation drug effects, Drug Resistance, Neoplasm drug effects, Female, Genes, p53, Humans, MutS Homolog 2 Protein genetics, Ovarian Neoplasms drug therapy, Ovarian Neoplasms genetics, Ovarian Neoplasms pathology, Bridged Bicyclo Compounds, Heterocyclic pharmacology, Drug Resistance, Neoplasm genetics, Lactones pharmacology, Macrolides pharmacology, Mutation, Tubulin genetics, Tubulin metabolism
- Abstract
Cancer cell lines selected for resistance to microtubule targeting agents (MTA) often have acquired mutations in the β-tubulin binding sites for these agents. Despite strong correlational evidence, the functional and quantitative significance of such mutations in the resistance to MTA remains unknown. We recently showed that peloruside A (PLA) and laulimalide (LAU)-resistant cancer cell lines, 1A9-R1 (R1) and 1A9-L4 (L4), generated through multi-step selection of human 1A9 ovarian cancer cells with high concentrations of either PLA (for R1) or LAU (for L4) have single distinct mutations in their βI-tubulin gene. The R1 cells have a mutation at amino acid position 296 (A296T), and the L4 cells have a mutation at position 306 (R306H/C), both of which lie at the putative binding sites of PLA and LAU. To gain insights on the functional role of these mutations in the resistance phenotype, R1 and L4 cells were transfected with wild type βI-tubulin. MTT cell proliferation assays revealed that restoration of wild type βI-tubulin expression partially sensitized the R1 and L4 cells to PLA and LAU. Cell cycle analysis and intracellular tubulin polymerization assays demonstrated that the increased sensitivity was correlated with an increased ability of PLA and LAU to induce G2-M arrest and tubulin polymerization in the cells. Unlike paclitaxel-selected clones of 1A9 cells, both R1 and L4 cells exhibited a functional p53 gene, and the abundance of the mismatch repair gene hMSH2 (human mutS homolog 2) was comparable to the parental 1A9 cells. This study provides the first direct evidence that A296 and R306 of βI-tubulin are important determinants of the PLA and LAU response in cancer cells.
- Published
- 2014
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31. UHPLC-MS analysis of juvenile hormone II in Mediterranean corn borer (Sesamia nonagrioides) hemolymph using various ionization techniques.
- Author
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Vilaró F, Pérez-Hedo M, Eras J, Canela R, and Eizaguirre M
- Subjects
- Animals, Atmospheric Pressure, Ions chemistry, Reproducibility of Results, Spectrometry, Mass, Electrospray Ionization methods, Zea mays, Chromatography, High Pressure Liquid methods, Hemolymph chemistry, Juvenile Hormones analysis, Mass Spectrometry methods, Moths chemistry, Sesquiterpenes analysis
- Abstract
The juvenile hormones (JHs) have been considered the most versatile hormones in the animal kingdom. JH-II is the most abundant JH in Sesamia nonagrioides, important maize pests in the Mediterranean basin. This study compared the sensitivities and matrix effects of four ionization modes on analyzing JH-II in S. nonagrioides hemolymph using ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS) in single ion monitoring (SIM) mode. The ionization techniques tested were electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), and APPI with the lamp turned off, which corresponds to atmospheric pressure thermospray ionization (APTSI). ESI was discarded because of the high matrix effect. APPI was discarded because the correlation responses between solvent and matrix on the instrumental quality parameters were worse than those for APTSI and APCI. In our analytical conditions, APCI has shown the best validation parameter values. APCI ionization is widely available in instrumental laboratories.
- Published
- 2012
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32. Fast determination of oleic acid in pork by flow injection analysis/mass spectrometry.
- Author
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Muñoz R, Vilaró F, Eras J, Estany J, and Tor M
- Subjects
- Animals, Chromatography, Gas, Fatty Acids, Linear Models, Reproducibility of Results, Swine, Time Factors, Flow Injection Analysis methods, High-Throughput Screening Assays methods, Meat analysis, Oleic Acid analysis, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
In some Mediterranean products such as olive oil or ham, oleic acid is the most abundant component of the total fat. Due to the large volume of trade in these products, it may be necessary to analyze oleic fatty acids in high numbers of samples in short periods of time. However, using classic lipid analysis techniques, it is not always possible to cope with these high demands. To solve this problem, a high-throughput analytical method for oleic fatty acid quantification in pork is presented. The purpose of the method is to avoid liquid chromatography processes using a flow injection analysis (FIA) system based on electrospray ionization mass spectrometry. The use of pentadecanoic fatty acid as an internal standard overcame matrix effects. The oleic FIA technique could be used as a suitable method for discriminating carcass samples for selection and labeling by oleic acid content when large numbers of pork samples must be processed in a short period of time., (Copyright © 2011 John Wiley & Sons, Ltd.)
- Published
- 2011
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33. From symmetric glycerol derivatives to dissymmetric chlorohydrins.
- Author
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Solarte C, Escribà M, Eras J, Villorbina G, Canela R, and Balcells M
- Subjects
- Magnetic Resonance Spectroscopy, Spectrometry, Mass, Electrospray Ionization, Spectroscopy, Fourier Transform Infrared, Chlorohydrins chemistry, Glycerol chemistry
- Abstract
The anticipated worldwide increase in biodiesel production will result in an accumulation of glycerol for which there are insufficient conventional uses. The surplus of this by-product has increased rapidly during the last decade, prompting a search for new glycerol applications. We describe here the synthesis of dissymmetric chlorohydrin esters from symmetric 1,3-dichloro-2-propyl esters obtained from glycerol. We studied the influence of two solvents: 1,4-dioxane and 1-butanol and two bases: sodium carbonate and 1-butylimidazole, on the synthesis of dissymmetric chlorohydrin esters. In addition, we studied the influence of other bases (potassium and lithium carbonates) in the reaction using 1,4-dioxane as the solvent. The highest yield was obtained using 1,4-dioxane and sodium carbonate.
- Published
- 2011
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34. Preparation of (S)-1-Halo-2-octanols Using Ionic Liquids and Biocatalysts.
- Author
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Oromí-Farrús M, Eras J, Sala N, Torres M, and Canela R
- Subjects
- Catalysis, Enzymes, Immobilized, Fungal Proteins, Lipase chemistry, Rhizomucor enzymology, Ionic Liquids chemistry, Octanols metabolism
- Abstract
Preparation of (S)-1-chloro-2-octanol and (S)-1-bromo-2-octanol was carried out by the enzymatic hydrolysis of halohydrin palmitates using biocatalysts. Halohydrin palmitates were prepared by various methods from palmitic acid and 1,2-octanediol. A tandem hydrolysis was carried out using lipases from Candida antarctica (Novozym 435), Rhizomucor miehei (Lipozyme IM), and "resting cells" from a Rhizopus oryzae strain that was not mycotoxigenic. The influence of the enzyme and the reaction medium on the selective hydrolysis of isomeric mixtures of halohydrin esters is described. Novozym 435 allowed preparation of (S)-1-chloro-2-octanol and (S)-1-bromo-2-octanol after 1-3 h of reaction at 40 degrees C in [BMIM][PF(6)].
- Published
- 2009
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35. Synthesis of allyl esters of fatty acids and their ovicidal effect on Cydia pomonella (L.).
- Author
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Escribà M, Barbut M, Eras J, Canela R, Avilla J, and Balcells M
- Subjects
- Animals, Female, Insecticides chemical synthesis, Lethal Dose 50, Moths growth & development, Ovum drug effects, Esters chemical synthesis, Esters pharmacology, Fatty Acids chemistry, Insecticides pharmacology, Moths drug effects
- Abstract
Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.
- Published
- 2009
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- View/download PDF
36. A rapid and reliable direct method for quantifying meat acylglycerides with monomode microwave irradiation.
- Author
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Tomàs A, Tor M, Villorbina G, Canela R, Balcells M, and Eras J
- Subjects
- Animals, Chromatography, Gas methods, Data Interpretation, Statistical, Esterification, Methanol chemistry, Temperature, Glycerides analysis, Meat analysis, Microwaves, Trimethylsilyl Compounds chemistry
- Abstract
A rapid methodology for direct analysis of meat acylglycerides is proposed. A transesterification is carried out in a microwave reactor consisting of a monomode oven using chlorotrimethylsilane (CTMS) and methanol. High-temperature gas chromatography was used to check the absence of underivatized acylglycerides. Whereas transesterification is complete after 30s at 90 degrees C in the microwave method, the reference method needs 2h to complete this process. Moreover, the CTMS-microwave method shows higher recoveries of individual saturated, monounsaturated and polyunsaturated fatty acids. No influence of microwave irradiation on the composition of the fatty acids was observed.
- Published
- 2009
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37. [BMIM][PF(6)] promotes the synthesis of halohydrin esters from diols using potassium halides.
- Author
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Oromí-Farrús M, Eras J, Villorbina G, Torres M, Llopis-Mestre V, Welton T, and Canela R
- Subjects
- Carboxylic Acids chemistry, Catalysis, Esters chemistry, Alcohols chemistry, Esters chemical synthesis, Halogens chemistry, Imidazoles chemistry, Potassium chemistry
- Abstract
Haloesterification of diverse diols with various carboxylic acids was achieved using potassium halides (KX) as the only halide source in ionic liquids. The best yield was obtained in [BMIM][PF(6)] when 1,2-octanediol, palmitic acid and KBr were used. This yield was 85% and the regioisomer with the bromine in primary position was present in a 75:25 ratio. The regioisomeric ratio could be improved using either KCl or some phenylcarboxylic acids. [BMIM][PF(6)] acts as both reaction media and catalyst of the reaction. To the best of our knowledge, this type of combined reaction using an ionic liquid is unprecedented. The other solvents tested did not lead either to the same yield or to the same regioisomeric ratio.
- Published
- 2008
- Full Text
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38. Direct quantitation of fatty acids present in bacteria and fungi: stability of the cyclopropane ring to chlorotrimethylsilane.
- Author
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Eras J, Oró R, Torres M, and Canela R
- Subjects
- Bacteria metabolism, Fatty Acids metabolism, Fungi metabolism, Temperature, Bacteria chemistry, Chemistry Techniques, Analytical methods, Cyclopropanes chemistry, Fatty Acids chemistry, Fungi chemistry, Trimethylsilyl Compounds chemistry
- Abstract
The stability of the cyclopropane ring and the fatty acid composition of microbial cells were determined using chlorotrimethylsilane as reagent with three different conditions 80 degrees C for 1 h, 60 degrees C for 1 h, and 60 degrees C for 2 h. Chlorotrimethylsilane permits a simultaneous extraction and derivatization of fatty acids. A basic method was used as reference. The bacteria, Escherichia coli, Burkholderia cepacia, and Lactobacillus brevis, and fungi Aspergillus niger and Gibberella fujikuroi were used. The stability of the cyclopropane ring on acidic conditions was tested using the cyclopropanecarboxylic acid and a commercial mixture of bacteria fatty acid methyl esters (BAME). Fisher's least significant difference test showed significant differences among the methods. The method using chlorotrimethylsilane and 1-pentanol for 1 h at 80 degrees C gave the best results in cyclopropane, hydroxyl, and total fatty acid recoveries. This procedure allows the fast and easy one-step direct extraction derivatization.
- Published
- 2008
- Full Text
- View/download PDF
39. Haemophilus influenzae CAPD peritonitis in an HIV-infected patient.
- Author
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Ghosh M and Eras J
- Subjects
- Adult, Ampicillin therapeutic use, Anti-Bacterial Agents therapeutic use, Female, Haemophilus Infections drug therapy, Humans, Peritonitis drug therapy, Peritonitis etiology, Renal Insufficiency therapy, HIV Infections complications, Haemophilus Infections microbiology, Haemophilus influenzae isolation & purification, Peritoneal Dialysis, Continuous Ambulatory, Peritonitis microbiology, Renal Insufficiency complications
- Abstract
Haemophilus influenzae is a rare causative organism of CAPD peritonitis. This is a report of the first case of H. influenzae CAPD peritonitis in a host with HIV. The patient was successfully treated with a two-week course of intraperitoneal ampicillin. Peritoneal dialysis catheter removal was not required.
- Published
- 2007
- Full Text
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40. Six years after the commercial introduction of Bt maize in Spain: field evaluation, impact and future prospects.
- Author
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Eizaguirre M, Albajes R, López C, Eras J, Lumbierres B, and Pons X
- Subjects
- Forecasting, Spain, Zea mays parasitology, Bacillus thuringiensis genetics, Genetic Engineering trends, Plants, Genetically Modified microbiology, Plants, Genetically Modified parasitology, Zea mays genetics, Zea mays microbiology
- Abstract
We carried out a 6-year-field evaluation to assess potential hazards of growing Compa, a transgenic Bt maize variety based on the transformation event CG 00256-176. Two categories of hazards were investigated: the potential of the target corn borer Sesamia nonagrioides to evolve resistance to Bt maize and effects on non-target organisms. In order to address the first hazard, dispersal capacity of the corn borer was measured and our results indicated that larvae move to plants other than those onto which the female oviposited - even to plants in adjacent rows - in remarkable numbers and they do so mostly at a mature age, suggesting that mixing Bt and non-Bt seeds in the same field would not be a very useful deployment strategy to delay/prevent resistance. In addition, adults move among fields to mate and males may do so for up to 400 m. Three different aspects of potential non-target effects were investigated: sub-lethal effects on the target S. nonagrioides, effects on non-target maize pests, and effects on maize-dwelling predators. Larvae collected in Bt fields at later growth stages, in which event 176 Bt maize expresses Bt toxin at sub-lethal concentrations, had longer diapause and post-diapause development than larvae collected in non-Bt fields, a feature that might lead to a certain isolation between populations in both type of fields and accelerate Bt resistance evolution. Transgenic maize did not have a negative impact on non-target pests in the field; more aphids and leafhoppers but similar numbers of cutworms and wireworms were counted in Bt versus non-Bt fields; in any case differences in damage or yield were recorded. We observed no difference in the numbers of the most relevant predators in fields containing transgenic or no transgenic maize.
- Published
- 2006
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41. Chlorotrimethylsilane, a reagent for the direct quantitative analysis of fats and oils present in vegetable and meat samples.
- Author
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Eras J, Ferran J, Perpiña B, and Canela R
- Subjects
- Fats analysis, Meat Products analysis, Oils analysis, Trimethylsilyl Compounds chemistry, Vegetables chemistry
- Abstract
Acylglycerides present in oil seeds and meat can be transformed into volatile fatty esters using chlorotrimethylsilane (CTMS) and 1-pentanol as reagents. The volatile esters can then be analysed by GC. The method is quantitative and involves only minor sample manipulation. It often permits major recoveries of the total saponifiable lipids present in solid samples. A 40 min reaction time is enough to ensure the total conversion of saponifiable lipids to the corresponding FAPEs.
- Published
- 2004
- Full Text
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42. Chlorotrimethylsilane: a suitable reagent for the synthesis of chlorohydrin esters.
- Author
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Eras J, Méndez JJ, Balcells M, and Canela R
- Abstract
A new methodology for obtaining chlorohydrin esters using a one-pot esterification-chlorination reaction, in which one of the reagents, chlorotrimethylsilane, acts as solvent, is described. The reaction is stereospecific and its regioselectivity depends on the number of carbons between the hydroxyl groups present in the starting material. A mechanism is proposed.
- Published
- 2002
- Full Text
- View/download PDF
43. Chlorotrimethylsilane as a reagent for gas chromatographic analysis of fats and oils.
- Author
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Eras J, Montañes F, Ferran J, and Canela R
- Subjects
- Esterification, Chromatography, Gas methods, Fats analysis, Indicators and Reagents chemistry, Oils analysis, Trimethylsilyl Compounds chemistry
- Abstract
Chlorotrimethylsilane can be used as a reagent to transform triglycerides into volatile fatty esters. The volatile esters can then be analysed by GC. The results are fully comparable to those obtained by alternative methods used worldwide. The new one-step method can transesterify acylglycerides and esterify free fatty acids at the same time. Chlorotrimethylsilane is cheaper than BF3-MeOH and is likely to permit the use of different alcohols.
- Published
- 2001
- Full Text
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44. NSAIDs and the kidney revisited: are selective cyclooxygenase-2 inhibitors safe?
- Author
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Eras J and Perazella MA
- Subjects
- Anti-Inflammatory Agents, Non-Steroidal adverse effects, Cyclooxygenase 1, Cyclooxygenase 2, Cyclooxygenase 2 Inhibitors, Cyclooxygenase Inhibitors adverse effects, Humans, Membrane Proteins, Prostaglandin-Endoperoxide Synthases, Prostaglandins metabolism, Renal Insufficiency etiology, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Cyclooxygenase Inhibitors therapeutic use, Isoenzymes antagonists & inhibitors, Kidney drug effects
- Abstract
Selective cyclooxygenase-2 (COX-2) inhibitors have provided relief for patients suffering from chronic pain and other inflammatory conditions and have reduced adverse gastrointestinal effects. The documented reduction in gastric erosions, ulcerations, and perforations during the use of COX-2-selective inhibitors raises the question: would the kidney be similarly spared? Our understanding of these enzyme isoforms in the kidney is incomplete. However, kidney tissue seems to possess "constitutive" or homeostatic COX-2 enzyme, suggesting a role for prostaglandins produced by this isoform. In addition, studies evaluating the renal effects of the selective nonsteroidal anti-inflammatory drugs (NSAIDs) are inconclusive, and available data on the renal effects of COX-2-selective inhibitors are conflicting. Inadequate numbers, varied baseline patient characteristics, and different doses and lengths of drug treatment hampers comparison of the small number of clinical investigations available for review. Therefore, this article reviews the role of cyclooxygenase enzyme activity and associated prostaglandins in the kidney and the adverse renal effects of nonselective NSAIDs. We also touch on the COX-1/COX-2 selectivity of NSAIDs, the localization of COX enzymes in kidneys, and clinical studies examining the renal effects of selective COX-2 inhibitors.
- Published
- 2001
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45. Are selective COX-2 inhibitors nephrotoxic?
- Author
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Perazella MA and Eras J
- Subjects
- Acute Disease, Aged, Celecoxib, Cyclooxygenase 2, Cyclooxygenase 2 Inhibitors, Female, Humans, Male, Membrane Proteins, Middle Aged, Pyrazoles, Cyclooxygenase Inhibitors adverse effects, Isoenzymes pharmacology, Peroxidases antagonists & inhibitors, Prostaglandin-Endoperoxide Synthases pharmacology, Renal Insufficiency chemically induced, Sulfonamides adverse effects
- Abstract
Nonsteroidal anti-inflammatory drugs are well-known culprits in the development of acute renal insufficiency in high-risk patients. The recent release of the selective cyclooxygenase-2 enzyme inhibitors for the treatment of inflammatory diseases and pain syndromes has been associated with a clear-cut decrease in adverse gastrointestinal effects. However, the nephrotoxic potential of these agents in patients with prostaglandin-dependent states and chronic renal impairment is unknown. Many clinicians commonly wonder if these agents can be safely prescribed to such high-risk patients. We present two cases of acute renal failure complicating the course of therapy with celecoxib in patients with chronic renal insufficiency.
- Published
- 2000
- Full Text
- View/download PDF
46. Severe digestive pathology associated with chronic Chagas' disease in Ecuador: report of two cases.
- Author
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Guevara AG, Eras JW, Recalde M, Vinueza L, Cooper PJ, Ouaissi A, and Guderian RH
- Subjects
- Aged, Animals, Antibodies, Protozoan blood, Chagas Disease diagnosis, Chronic Disease, DNA, Protozoan blood, Digestive System Diseases diagnosis, Ecuador, Female, Humans, Male, Middle Aged, Polymerase Chain Reaction, Trypanosoma cruzi genetics, Trypanosoma cruzi immunology, Chagas Disease complications, Digestive System Diseases etiology
- Abstract
DNA extracted from peripheral blood of two Ecuadorian patients showing severe digestive pathology was amplified by the polymerase chain reaction using a Trypanosoma cruzi specific oligonucleotide primers derived from the primary sequence of a cDNA encoding for a 24 kDa excretory/secretory protein. The positive PCR results together with the clinical findings confirmed that both patients had a digestive pathology due to Chagas' disease. This pathology could be more frequent than previously described in the chagasic endemic regions of Andean countries.
- Published
- 1997
- Full Text
- View/download PDF
47. Proteoglycans partially co-purify with RNA in TRI Reagent and can be transferred to filters by northern blotting.
- Author
-
Schick BP and Eras J
- Subjects
- Autoradiography, Humans, Indicators and Reagents, Megakaryocytes chemistry, Membranes, Artificial, Molecular Weight, Tumor Cells, Cultured chemistry, Blotting, Northern methods, Proteoglycans isolation & purification, RNA isolation & purification
- Published
- 1995
48. Phosphorothioate oligonucleotides cause degradation of secretory but not intracellular serglycin proteoglycan core protein in a sequence-independent manner in human megakaryocytic tumor cells.
- Author
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Schick BP, Eras JL, and Mintz PS
- Subjects
- Base Sequence, Catalase pharmacology, Cell Line, Codon, Electroporation, Humans, Leukemia, Erythroblastic, Acute, Molecular Sequence Data, Proteoglycans drug effects, Proteoglycans metabolism, Superoxide Dismutase pharmacology, Thrombocythemia, Essential, Tumor Cells, Cultured, Vesicular Transport Proteins, Gene Expression drug effects, Oligodeoxyribonucleotides pharmacology, Oligonucleotides, Antisense pharmacology, Proteoglycans biosynthesis, Proteoglycans genetics, Thionucleotides
- Abstract
Human megakaryocytic tumor cell lines CHRF-288-11 and HEL (human erythroleukemia) were incubated with antisense phosphodiester (PDE) and phosphorothioate (PS) oligodeoxynucleotides directed against the first six codons of the human serglycin proteoglycan gene. As controls, PDE scrambled and PS sense and scrambled sequences and a probe antisense to a 3' portion of the coding sequence were used. Treatment with PDE-ODNs did not alter the core protein content of cell or culture medium proteoglycans. Treatment with all the PS-ODNs resulted in loss of the 31 kD serglycin core protein in the medium, but not the cell-associated proteoglycans, and concomitant appearance of a heavily labeled core protein band at the dye front. This band appears to arise from truncation of the core protein, which leaves the glycosaminoglycan attachment region intact. The higher molecular weight core proteins, which appear to be derived from a betaglycan-like proteoglycan, were not affected by the PDE or PS-ODN treatment. The same effect was seen with or without electroporation, which was used to enhance uptake of the ODNs. Thus treatment of megakaryocytic tumor cells with PS-ODNs appeared to cause a selective degradation of the serglycin core protein in a sequence-independent manner. Degradation most likely occurred intracellularly, because culture supernatants did not degrade exogenously added serglycin proteoglycan, and the presence of superoxide dismutase and catalase in the culture medium during exposure of the cells to the PS-ODNs did not prevent the degradation.
- Published
- 1995
- Full Text
- View/download PDF
49. Hydrolysis of cholesteryl oleate in vitro by ovarian homogenates from non-pregnant and pregnant rabbits.
- Author
-
Morin RJ, Eras J, and Martin SC
- Subjects
- Animals, Carbon Isotopes, Cholesterol analysis, Colorimetry, Female, Hydrogen-Ion Concentration, In Vitro Techniques, Oleic Acids metabolism, Ovary analysis, Pregnancy, Rabbits, Cholesterol metabolism, Ovary metabolism, Pregnancy, Animal
- Published
- 1969
- Full Text
- View/download PDF
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