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Protein Extraction (protein + extraction)
Selected AbstractsProteomics in globe artichoke: Protein extraction and sample complexity reduction by PEG fractionationELECTROPHORESIS, Issue 9 2009Alberto Acquadro Abstract Here, we report the first leaf proteome analysis for globe artichoke. Three protein extraction protocols were tested and a reproducible Mg/NP-40-based method was established. Ribulose-1,5-biphosphate carboxylase-oxygenase (RuBisCO) is a highly abundant leaf protein, and its presence masks co-localizing, less abundant proteins. To remove RuBisCO from the sample, and thereby improve spot resolution, a PEG fractionation approach was elaborated. 2-DE profiles of various PEG fractions showed that the fractionation procedure was successful in excluding most of the RuBisCO, allowing for the detection of many low-abundance proteins. Western blot analysis was able to confirm the reduction in RuBisCO content achieved by PEG fractionation. In all, 841 distinct protein spots were detected, and 40 of these, selected from the RuBisCO region of the 2-DE profile, were successfully identified by MS. A number of homologues of these proteins also co-localize with RuBisCO in Arabidopsis thaliana. [source] Protein extraction for 2-DE from the lamina of Ecklonia kurome (laminariales): Recalcitrant tissue containing high levels of viscous polysaccharidesELECTROPHORESIS, Issue 3 2008Kouhei Nagai Abstract Extraction of proteins from the tissues of laminarialean algae, i.e. kelp, is difficult due to high levels of nonprotein interfering compounds, mainly viscous polysaccharides. To establish proteomic analysis of kelp species, an ethanol/phenol extraction method was developed and compared to other popular methods. Proteins were extracted with phenol from crude protein powder, obtained by homogenizing the kelp tissues in ice-cold ethanol. The ethanol/phenol method produced high-quality proteins of the highest purity from the lamina of Ecklonia kurome, one of the Japanese dominant laminarialean algae. This method gave well-resolved 1-D SDS-PAGE or 2-DE images with low background and the highest number of bands or spots. In particular, proteins with neutral to basic pI,s were efficiently extracted. Furthermore, 27 spots on the 2-DE gel were extensively identified by MALDI-TOF/TOF analysis. To the best of our knowledge, this is the first report of a protocol for protein extraction from kelp tissues that gives satisfactory 2-D protein profiles. It is expected that the protocol can be applied to other algae tissues or other recalcitrant plant tissues containing high levels of nonprotein interfering compounds. [source] Aqueous Extraction and Membrane Isolation of Protein from Defatted Gevuina avellanaJOURNAL OF FOOD SCIENCE, Issue 2 2002A. Moure ABSTRACT: Proteins from defatted Gevuina avellana seeds were extracted in aqueous media. Protein extraction was limited at liquid-to-solid ratios under 12 g/g, but was not significantly affected by temperatures in the 25 to 45 °C range. The maximum protein extractability occurred both at acidic and alkaline pH; the presence and concentration of NaCl affected it differently, depending on the extraction pH. Up to 3 extraction stages with whey recycle after ultrafiltration were performed, without affecting the protein extraction yield. The functional properties of the protein isolated with membranes were similar or better than those from isoelectric precipitation. [source] Sugarcane proteomics: Establishment of a protein extraction method for 2-DE in stalk tissues and initiation of sugarcane proteome reference mapELECTROPHORESIS, Issue 12 2010Ramesh Sundar Amalraj Abstract Sugarcane is an important commercial crop cultivated for its stalks and sugar is a prized commodity essential in human nutrition. Proteomics of sugarcane is in its infancy, especially when dealing with the stalk tissues, where there is no study to date. A systematic proteome analysis of stalk tissue yet remains to be investigated in sugarcane, wherein the stalk tissue is well known for its rigidity, fibrous nature, and the presence of oxidative enzymes, phenolic compounds and extreme levels of carbohydrates, thus making the protein extraction complicated. Here, we evaluated five different protein extraction methods in sugarcane stalk tissues. These methods are as follows: direct extraction using lysis buffer (LB), TCA/acetone precipitation followed by solubilization in LB, LB containing thiourea (LBT), and LBT containing tris, and phenol extraction. Both quantitative and qualitative protein analyses were performed for each method. 2-DE analysis of extracted total proteins revealed distinct differences in protein patterns among the methods, which might be due to their physicochemical limitations. Based on the 2-D gel protein profiles, TCA/acetone precipitation-LBT and phenol extraction methods showed good results. The phenol method showed a shift in pI values of proteins on 2-D gel, which was mostly overcome by the use of 2-D cleanup kit after protein extraction. Among all the methods tested, 2-D cleanup-phenol method was found to be the most suitable for producing high number of good-quality spots and reproducibility. In total, 30 and 12 protein spots commonly present in LB, LBT and phenol methods, and LBT method were selected and subjected to eLD -IT-TOF-MS/MS and nESI-LC-MS/MS analyses, respectively, and a reference map has been established for sugarcane stalk tissue proteome. A total of 36 nonredundant proteins were identified. This is a very first basic study on sugarcane stalk proteome analysis and will promote the unexplored areas of sugarcane proteome research. [source] Protein extraction for 2-DE from the lamina of Ecklonia kurome (laminariales): Recalcitrant tissue containing high levels of viscous polysaccharidesELECTROPHORESIS, Issue 3 2008Kouhei Nagai Abstract Extraction of proteins from the tissues of laminarialean algae, i.e. kelp, is difficult due to high levels of nonprotein interfering compounds, mainly viscous polysaccharides. To establish proteomic analysis of kelp species, an ethanol/phenol extraction method was developed and compared to other popular methods. Proteins were extracted with phenol from crude protein powder, obtained by homogenizing the kelp tissues in ice-cold ethanol. The ethanol/phenol method produced high-quality proteins of the highest purity from the lamina of Ecklonia kurome, one of the Japanese dominant laminarialean algae. This method gave well-resolved 1-D SDS-PAGE or 2-DE images with low background and the highest number of bands or spots. In particular, proteins with neutral to basic pI,s were efficiently extracted. Furthermore, 27 spots on the 2-DE gel were extensively identified by MALDI-TOF/TOF analysis. To the best of our knowledge, this is the first report of a protocol for protein extraction from kelp tissues that gives satisfactory 2-D protein profiles. It is expected that the protocol can be applied to other algae tissues or other recalcitrant plant tissues containing high levels of nonprotein interfering compounds. [source] An efficient protein preparation for proteomic analysis of developing cotton fibers by 2-DEELECTROPHORESIS, Issue 22 2006Yuan Yao Abstract Preparation of high-quality proteins from cotton fiber tissues is difficult due to high endogenous levels of polysaccharides, polyphenols, and other interfering compounds. To establish a routine procedure for the application of proteomic analysis to cotton fiber tissues, a new protocol for protein extraction was developed by optimizing a phenol extraction method combined with methanol/ammonium acetate precipitation. The protein extraction for 2-DE was remarkably improved by the combination of chemically and physically modified processes including polyvinylpolypyrrolidone (PVPP) addition, acetone cleaning, and SDS replacement. The protocol gave a higher protein yield and vastly greater resolution and spot intensity. The efficiency of this protocol and its feasibility in fiber proteomic study were demonstrated by comparison of the cotton fiber proteomes at two growth stages. Furthermore, ten protein spots changed significantly were identified by MS/tandem MS and their potential relationships to fiber development were discussed. To the best of our knowledge, this is the first time that a protocol for protein extraction from cotton fiber tissues appears to give satisfactory and reproductive 2-D protein profiles. The protocol is expected to accelerate the process of the proteomic study of cotton fibers and also to be applicable to other recalcitrant plant tissues. [source] A universal and rapid protocol for protein extraction from recalcitrant plant tissues for proteomic analysisELECTROPHORESIS, Issue 13 2006Wei Wang Dr. Abstract A simple and universally applicable protocol for extracting high-quality proteins from recalcitrant plant tissues is described. We have used the protocol with no modification, for a wide range of leaves and fruits. In all cases, this protocol allows to obtain good electrophoretic separation of proteins. As the protocol is rapid, universal, and compatible with silver staining, it could be used for routine protein extraction from recalcitrant plant tissues for proteomic analysis. [source] High-efficiency protein extraction from polyacrylamide gels for molecular mass measurement by matrix-assisted laser desorption/ionization-time of flight-mass spectrometryELECTROPHORESIS, Issue 6 2005Ya Jin Abstract A simple and fast method of protein extraction from Coomassie Brilliant Blue (CBB)-stained polyacrylamide gels suited for molecular mass measurement of proteins by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) is reported. Proteins in CBB-stained gel pieces were extracted by a 10-min soaking in 0.1,M NaOH at 25°C. The recovery of this one-step extraction method was 34,73% for proteins <67,kDa. CBB adduction to proteins during mass spectrometric analysis was avoided by a destaining step before the alkaline extraction. The molecular mass values of the extracted proteins coincided with those of purified proteins within ±0.01,0.10% deviation for all the proteins <36,kDa. Because of the high extraction recovery, mass measurement was possible for the proteins extracted from CBB-stained gels with loaded protein quantities as little as 34,ng for cytochrome,c, ,-lactalbumin, myoglobin, ,-lactoglobulin, trypsinogen, and carbonic anhydrase (12.4,29.0,kDa), 340,ng for glyceraldehyde-3-phosphate dehydrogenase (35.6,kDa) and albumin (66.3,kDa). This method provides a highly efficient approach to utilize CBB-stained one- or two-dimensional gels for whole protein analysis using MALDI-TOF-MS. [source] Spinning of protein fibres from blue squat lobster (Cervimunida jhoni) industry by-productsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2007Mario Pérez-Won Summary The fresh whole crustaceans by-products from blue squat lobster (Cervimunida jhoni) were minced and the protein was solubilised with 0.1 m of NaOH. Then the solution was centrifuged and the supernatant was precipitated using 0.1 m of HCl. The dope was prepared with 4% of protein, solid NaOH and coadjutant (sodium alginate or carragenan). The dope was extruded through the trial-spinning machine and the fibre was formed. The results showed that the best condition of protein extraction was 90 min and pH 12.5 when 58.4% of protein from whole crustacean by-products could be extracted. The protein isolate was obtained at pH 4.0. The best fibres were obtained when the ratios protein/NaOH, and protein/coadjutant were 10:1 and 1:1 respectively. Rheological measurements of all dopes exhibited non-Newtonian behaviour and the experimental data were described by the power law model. The consistency index (k) of the dopes containing carragenan seem to be a parameter to evaluate dope spinnability. [source] Optimizing protein extraction from plant tissues for enhanced proteomics analysisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 11 2008Wei Wang Abstract Plant tissues usually contain high levels of proteases and secondary metabolites that severely interfere with protein extraction, separation, and identification. Preparation of high-quality protein samples from plant tissues for proteomic analysis represents a great challenge. This article briefly describes the critical points in protein separation, especially secondary metabolites in plant tissues, and removal strategy. It provides an updated overview of three total protein extraction methods and their applications in proteomic analysis of various recalcitrant tissues. [source] The content and distribution of condensed tannins in different species of the genus sorghum (Sorghum Moench) and their effect on seed protein electrophoresis,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2009Min-Xuan Liu Abstract BACKGROUND: The interaction between condensed tannins (CTs) and seed protein in varieties of sorghum interferes with protein extraction and the separation by electrophoresis, so electrophoresis can not be used widely for determining seed purity and identifying a variety. The objective of this research was to classify the effect of CTs on the extraction of seed storage proteins and on their analysis by SDS,PAGE, and to search for a promising solution to reduce the negative effect of CTs in sorghum. RESULTS: The vanillin,HCl test confirmed that CTs were localised mainly in the glumes of grain sorghum, but distributed in every fraction of sudangrass. Samples with high CT content did not produce any bands in the gel after electrophoresis. Removal of the glumes and pericarp/testa prevented the influence of CTs on electrophoresis for grain sorghum but had little effect for sudangrass. Adding tannin/catechin to the protein extraction of sorghum kernel decreased the number of bands in the gel. Adding polyvinylpyrrolidine to the protein extraction of sudangrass increased the bands. CONCLUSION: Tannin,protein interactions are responsible for the absence of bands in varieties with high CT content. For grain sorghum, decortication can prevent the influence. Adding polyvinylpyrrolidine during the extraction of seed protein could solve the problem of tannin,protein interactions for varieties of sudangrass. Copyright © 2009 Society of Chemical Industry [source] Inorganic phosphate has a crucial effect on Cry3Aa , -endotoxin productionLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2005A. Kurt Abstract Aims:, The study aimed at increasing Cry3Aa , -endotoxin production by a local isolate of Bacillus thuringiensis (B.t. strain Mm2). To this end, different nutritional conditions were tested for their effects on Cry3Aa yields. Methods and Results:,Bacillus thuringiensis Mm2 was grown by shaking at 30°C in different media. Samples were taken from the cultures at intervals and used for protein extraction. SDS-PAGE was performed for toxin analysis. Inclusion of inorganic phosphate (Pi) into the Difco's sporulation medium at an increased level of 200 mmol l,1 caused a fivefold increase (from 3 to 15·6 ,g ml,1) in toxin production. Omission of FeSO4 from the medium decreased this yield by half. Resuspension experiments suggested catabolite repression of toxin biosynthesis by glucose. The inclusion of high Pi invariably increased toxin synthesis, even in the absence of sugars. Conclusions:, Inorganic phosphate had the most striking effect on toxin biosynthesis. Iron effect was found to be unique to our isolate whereas Pi effect seemed to be common to the biosynthesis of Cry3Aa-type toxins. Stimulation of toxin synthesis by Pi did not seem to represent a relief from glucose repression. Significance and Impact of the Study:,Bacillus thuringiensis is the most versatile biopesticide for use in pest management. Regarding cost-effectiveness of related fermentations, high Pi supplement drastically increases Coleoptera-specific toxin synthesis. [source] Comparative LC-MS: A landscape of peaks and valleysPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2008Antoine H. P. America Dr. Abstract Quantitative proteomics approaches using stable isotopes are well-known and used in many labs nowadays. More recently, high resolution quantitative approaches are reported that rely on LC-MS quantitation of peptide concentrations by comparing peak intensities between multiple runs obtained by continuous detection in MS mode. Characteristic of these comparative LC-MS procedures is that they do not rely on the use of stable isotopes; therefore the procedure is often referred to as label-free LC-MS. In order to compare at comprehensive scale peak intensity data in multiple LC-MS datasets, dedicated software is required for detection, matching and alignment of peaks. The high accuracy in quantitative determination of peptide abundancies provides an impressive level of detail. This approach also requires an experimental set-up where quantitative aspects of protein extraction and reproducible separation conditions need to be well controlled. In this paper we will provide insight in the critical parameters that affect the quality of the results and list an overview of the most recent software packages that are available for this procedure. [source] A strategy for high-resolution protein identification in surface-enhanced laser desorption/ionization mass spectrometry: Calgranulin A and chaperonin 10 as protein markers for endometrial carcinomaPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2005Jingzhong Guo Abstract Surface-enhanced laser desorption/ionization-mass spectrometry (SELDI-MS) has conventionally been practiced on linear time of flight (TOF) which has low mass accuracy and resolution. Here we demonstrate in an examination of both malignant and nonmalignant endometrial tissue homogenates that high mass accuracy and resolution in the MS stage are crucial. Using a commercially available quadrupole/TOF (QqTOF), we were able to resolve two potential cancer markers, subsequently identified off-line as chaperonin 10 and calgranulin A, that differ by 8 Da in mass. Two off-line protein identification protocols were developed: the first was based on size-exclusion chromatography (SEC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), protein extraction, trypsin digestion, and matrix-assisted laser desorption/ionization-tandem MS (MALDI-MS/MS); the second on SEC and shotgun nano-liquid chromatography (nanoLC)-MS/MS. Analyses on a cohort of 44 endometrial homogenates showed 22 out of 23 nonmalignant samples had nondetectable to very low abundance of chaperonin 10 and calgranulin A; 17 of the 21 malignant samples had detectable to abundant levels of both proteins. Immunohistochemical staining of a tissue microarray of 32 samples showed that approximately half of malignant endometrial tissues exhibited positive staining for calgranulin A in the malignant epithelium, while 9 out of 10 benign tissues exhibited negative epithelial staining. In addition, macrophages/granulocytes in malignant as well as nonmalignant tissues showed positive staining. No immunostaining occurred in stroma or myometrium. Calgranulin A, in combination with chaperonin 10 and other proteins, may eventually constitute a panel of markers to permit diagnosis and screening of endometrial cancer. [source] A metal-chelate affinity reverse micellar system for protein extractionBIOTECHNOLOGY PROGRESS, Issue 1 2010Xiao-Yan Dong Abstract A new nonionic reverse micellar system is developed by blending two nonionic surfactants, Triton X-45 and Span 80. At total surfactant concentrations lower than 60 mmol/L and molar fractions of Triton X-45 less than 0.6, thermodynamically stable reverse micelles of water content (W0) up to 30 are formed. Di(2-ethylhexyl) phosphoric acid (HDEHP; 1,2 mmol/L) is introduced into the system for chelating transition metal ions that have binding affinity for histidine-rich proteins. HDEHP exists in a dimeric form in organic solvents and a dimer associated with one transition metal ion, including copper, zinc, and nickel. The copper-chelate reverse micelles (Cu-RM) are characterized for their W0, hydrodynamic radius (Rh), and aggregation number (Nag). Similar with reverse micelles of bis-2-ethylhexyl sodium sulfosuccinate (AOT), Rh of the Cu-RM is also linearly related to W0. However, Nag is determined to be 30,90 at W0 of 5,30, only quarter to half of the AOT reverse micelles. Then, selective metal-chelate extraction of histidine-rich protein (myoglobin) by the Cu-RM is successfully performed with pure and mixed protein systems (myoglobin and lysozyme). The solubilized protein can be recovered by stripping with imidazole or ethylinediaminetetraacetic acid (EDTA) solution. Because various transition metal ions can be chelated to the reverse micelles, it is convinced that the system would be useful for application in protein purification as well as simultaneous isolation and refolding of recombinant histidine-tagged proteins expressed as inclusion bodies. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Fractionation of transgenic corn seed by dry and wet milling to recover recombinant collagen-related proteinsBIOTECHNOLOGY PROGRESS, Issue 5 2009Cheng Zhang Abstract Corn continues to be considered an attractive transgenic host for producing recombinant therapeutic and industrial proteins because of its potential for producing recombinant proteins at large volume and low cost as coproducts of corn seed-based biorefining. Efforts to reduce production costs have been primarily devoted to increasing accumulation level, optimizing protein extraction conditions, and simplifying the purification. In the present work, we evaluated two grain fractionation methods, dry milling and wet milling, to enrich two recombinant collagen-related proteins; thereby, reducing the amount and type of corn-derived impurities in subsequent protein extraction and purification steps. The two proteins were a full-length human recombinant collagen type I alpha 1(rCI,1) chain with telopeptides and peptide foldon to effect triple helix formation and a 44-kDa rCI,1 fragment. For each, ,60% of the rCI,1s in the seed was recovered in the dry-milled germ-rich fractions making up ca. 25% of the total kernel mass. For wet milling, ,60% of each was recovered in three fractions accounting for 20,25% of the total kernel mass. The rCI,1s in the dry-milled germ-rich fractions were enriched three to six times compared with the whole corn kernel, whereas the rCI,1s were enriched 4,10 times in selected wet-milled fractions. The recovered starch from wet milling was almost free of rCI,1. Therefore, it was possible to generate rCI,1-enriched fractions by both dry and wet milling along with rCI,1-free starch using wet milling. Because of its simplicity, the dry milling procedure could be accomplished on-farm thus minimizing the risk of inadvertent release of viable transgenic seeds. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Protein Fractionation of Cowpea (Vigna unguiculata (L.) Walp) Leaf, Flower and Seed by Capillary Electrophoresis and Its Potential for Variety IdentificationCHINESE JOURNAL OF CHEMISTRY, Issue 4 2010Sirithon Siriamornpun Abstract The proteins of different faction of cowpea [Vigna unguiculata (L.) Walp] were fractionated by capillary electrophoresis (CE). The extracting solvent system was one of the most critical factors in the optimization exercise. To improve reproducibility, seed samples needed to be defatted with chloroform/methanol (V:V=2:1) as preferred prior to protein extraction. Proteins were extracted from seeds, leaves and flowers with 50% aqueous 1-propanol and separated on a 50 (m×20 cm fused silica capillary column using a UV detector at 200 nm. Separation was conducted at constant voltage (10 kV, 40°C), using iminodiacetic acid (pH 2.5) containing 0.05% hydroxypropylmethylcellulose (HPMC) and 20% acetonitile. The results showed that proteins extracted from all fraction of cowpea were successfully separated by CE in less than 20 min. Seed extracts provided the greatest number of eluted protein peaks, followed by flower and leaf, respectively. The seed-protein extracts provided unique CE patterns for different varieties; hence the seed was the tissue chosen as being most suitable for variety identification. As a result, an optimized procedure was developed to provide rapid identification of cowpea varieties, based on capillary electrophoregram patterns. [source] Reproducibility, sensitivity and compatibility of the ProteoExtract® subcellular fractionation kit with saturation labeling of laser microdissected tissuesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 16 2009Sonal Sawhney Abstract Laser microdissection (LMD), a method of isolating specific microscopic regions of interest from a tissue that has been sectioned, is increasingly being applied to study proteomics. LMD generally requires tissues to be fixed and histologically stained, which can interfere with protein recovery and subsequent analysis. We evaluated the compatibility and reproducibility of protein extractions from laser microdissected human colon mucosa using a subcellular fractionation kit (ProteoExtract®, Calbiochem). Four protein fractions corresponding to cytosol (fraction 1), membrane/organelle (fraction 2), nucleus (fraction 3) and cytoskeleton (fraction 4) were extracted, saturation labeled with Cy5 and 5,,g separated by both acidic (pH 4,7) and basic (pH 6,11) 2-DE. The histological stains and fixation required for LMD did not interfere with the accurate subcellular fractionation of proteins into their predicted fraction. The combination of subcellular fractionation and saturation CyDye labeling produced very well resolved, distinct protein spot maps by 2-DE for each of the subcellular fractions, and the total number of protein spots consistently resolved between three independent extractions for each fraction was 893, 1128, 1245 and 1577 for fractions 1, 2, 3 and 4, respectively. Although significant carryover of protein did occur between fractions, this carryover was consistent between experiments, and very low inter-experimental variation was observed. In summary, subcellular fractionation kits are very compatible with saturation labeling DIGE of LMD tissues and provide greater coverage of proteins from very small amounts of microdissected material. [source] Potential role of the cannabinoid receptor CB1 in the pathogenesis of erosive and non-erosive gastro-oesophageal reflux diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2010C. Calabrese Aliment Pharmacol Ther 2010; 32: 603,611 Summary Background, Cannabinoid (CB) receptors have been located in brain areas involved in the triggering of TLESRs as well as in the nodose ganglion from which vagal afferents emanate. The distribution of CB1 receptors has been investigated in the human gastrointestinal mucosa, as expression of inflammatory process. Aim, To evaluate the CB1 expression in oesophageal mucosa. Methods, A total of 87 consecutive subjects were enrolled: 10 controls, 39 NERD and 38 erosive oesophagitis. Eight specimens were taken from macroscopically normal mucosa. Five were processed by haematoxylin,eosin, MIB1/CB1 evaluation and three for the RNA and proteins extraction. Results, The mean MIB1-LI value was 31% and 22% in NERD and ERD patients, respectively, compared to 68% in the healthy subjects. Mean CB1mRNA/GUSB mRNA value of the controls was 0.66, while in GERD patients, it was 0.28. In NERD and ERD, the mean values of CB1/GUSB were 0.38 and 0.17, respectively, with highly significant differences between the NERD vs. ERD groups. Semi-quantitative analysis of CB1 expression, performed with WB, shows in NERD patients a higher CB1 receptor expression than ERD patients. Conclusions, With this study, we showed for the first time the presence of CB1 receptors in the human oesophageal epithelium. [source] | |||||||||||||