scholarly journals Gluten Immunogenic Peptides as Standard for the Evaluation of Potential Harmful Prolamin Content in Food and Human Specimen

2018 ◽  
Author(s):  
Ángel Cebolla ◽  
María de Lourdes Moreno ◽  
Laura Coto ◽  
Carolina Sousa
Keyword(s):  
Storage Proteins ◽  
Biological Fluids ◽  
Complex Mixture ◽  
Standard Reference Materials ◽  
Gluten Free ◽  
Immunogenic Peptides ◽  
Partial Digestion ◽  
Human Specimen ◽  
Main Components

Gluten is a complex mixture of storage proteins in cereals like wheat, barley and rye. Prolamins are the main components of gluten. Their high content in proline and glutamine makes them water-insoluble and difficult to digest in the gastrointestinal tract. Partial digestion generates peptide sequences which trigger immune responses in celiac and gluten-sensitive patients. Gluten detection in food is challenging because of the diversity, in various food matrices, of protein proportions and their immunogenicity. Attempts to develop standard reference materials have been unsuccessful. We present here a summary of recent studies reporting the detection of dominant Gluten Immunogenic Peptides (GIP) sharing epitopes presented in the α-gliadin 33-mer, the most important celiac disease-immunogenic sequence within gluten. GIP were not only detectable and quantifiable in very different kind of difficult to analyze food, but also in stool and urine of celiac patients on a supposedly gluten-free diet (GFD), providing the first simple and objective means to assess adherence to the GFD. Methods to specifically and sensitively detect the most active GIP in food and biological fluids are rational candidates may use similar analytical standard references for determination of the immunopathological risk of gluten exposure in gluten-related diseases.

scholarly journals Gluten Immunogenic Peptides as Standard for the Evaluation of Potential Harmful Prolamin Content in Food and Human Specimen

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1927 ◽  
Author(s):  
Ángel Cebolla ◽  
María Moreno ◽  
Laura Coto ◽  
Carolina Sousa
Keyword(s):  
Storage Proteins ◽  
Biological Fluids ◽  
Cell Activity ◽  
Complex Mixture ◽  
The Body ◽  
Standard Reference Materials ◽  
Immunogenic Peptides ◽  
Partial Digestion ◽  
Human Specimen ◽  
Main Components

Gluten is a complex mixture of storage proteins in cereals like wheat, barley, and rye. Prolamins are the main components of gluten. Their high content in proline and glutamine makes them water-insoluble and difficult to digest in the gastrointestinal tract. Partial digestion generates peptide sequences which trigger immune responses in celiac and gluten-sensitive patients. Gluten detection in food is challenging because of the diversity, in various food matrices, of protein proportions or modifications and the huge number of immunogenic sequences with differential potential immunoactivity. Attempts to develop standard reference materials have been unsuccessful. Recent studies have reported the detection of a limited number of dominant Gluten Immunogenic Peptides (GIP) that share similarities to epitopes presented in the α-gliadin 33-mer, which showed to be highly proteolytic resistant and is considered to be the most immunodominant peptide within gluten in celiac disease (CD). GIP were detectable and quantifiable in very different kind of difficult to analyze food, revealing the potential immunogenicity by detecting T-cell activity of celiac patients. But GIP were also found in stool and urine of celiac patients on a supposedly gluten-free diet (GFD), showing the capacity to resist and be absorbed and excreted from the body, providing the first simple and objective means to assess adherence to the GFD. Methods to specifically and sensitively detect the most active GIP in food and biological fluids are rational candidates may use similar analytical standard references for determination of the immunopathological risk of gluten exposure in gluten-related diseases.

scholarly journals Individual variability in patterns and dynamics of fecal gluten immunogenic peptides excretion after low gluten intake

2022 ◽  
Author(s):  
Laura Coto ◽  
Carolina Sousa ◽  
Angel Cebolla
Keyword(s):  
Interindividual Variability ◽  
Elisa Test ◽  
Individual Variability ◽  
High Variability ◽  
Detection Methods ◽  
Lateral Flow Immunoassay ◽  
Gluten Free ◽  
Immunogenic Peptides ◽  
Stool Samples

Abstract Purpose Determination of Gluten Immunogenic Peptides (GIP) in feces is a direct tool for gluten exposure detection. The sensitivity of GIP detection methods for cases of unintentional low gluten intakes is unknown. We studied the interindividual variability in the kinetic of excretion under homogeneously controlled dietary conditions, and the sensitivity of fecal GIP tests after low amounts of punctual gluten ingestions. Methods Participants (n = 20) followed the same gluten-free menu for 12 days in which two separated doses of gluten (50 mg and 2 g) were ingested and all the depositions were collected. GIP from stool samples were analyzed by ELISA and lateral flow immunoassay (LFIA) tests. Results Most participants had detectable GIP after 50 mg and 2 g gluten ingestions using ELISA test (72.2% and 95%, respectively), whereas the LFIA test showed less sensitivity (22.2% and 80%, respectively). GIP were detected at higher either frequency or concentration in the range of 12–36 h after 50 mg intake, and 12–84 h after 2 g consumption. Considering this period, diagnostic sensitivity of GIP detection after a single 50 mg ingestion may be significatively increased analyzing three stool samples per individual. High variability among participants was found in the time and amount of GIP excretion; however, some individuals showed common patterns for both gluten intakes. Conclusion Sporadic gluten exposure detection may require several fecal samples to achieve level of sensitivity above 90%. Interindividual variability in the dynamic of GIP excretion may suggest patterns of gluten metabolism.

scholarly journals Dynamics and Considerations in the Determination of the Excretion of Gluten Immunogenic Peptides in Urine: Individual Variability at Low Gluten Intake

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2624
Author(s):  
Laura Coto ◽  
Carolina Sousa ◽  
Angel Cebolla
Keyword(s):  
Celiac Disease ◽  
False Negative ◽  
Individual Variability ◽  
Lateral Flow Immunoassay ◽  
Gluten Free ◽  
Negative Results ◽  
Immunogenic Peptides ◽  
False Negative Results ◽  
Healthy Participants

Background: A lifelong strict gluten-free diet is the only available treatment for celiac disease, but total exclusion of gluten is difficult to achieve. The aim of this study was to determine the range of time and the amount of gluten immunogenic peptides (GIP) excreted in urine after specific gluten ingestions. Methods: 20 healthy participants followed the same diet for 12 days in which 50 mg and 2 g of gluten were ingested and all the urinations were collected. GIP were analyzed by lateral flow immunoassay (LFIA) tests and quantified using an LFIA reader. Results: GIP were detected in 15% and 95% of participants after 50 mg and 2 g gluten intakes, respectively. The higher frequency and concentration of GIP was found between 6 and 9 h after both gluten ingestions. The ranges of detection were 3–12 h (50 mg) and 0–15 h (2 g). Conclusions: An increase in the frequency of urine tests may be a suitable approach to avoid false negative results. The use of the LFIA test in three urine samples collected at different times may show a sensitivity of 19.6% for a gluten ingestion like 50 mg, increasing to 93% after 2 g consumption.

scholarly journals A highly sensitive and selective spectrophotometric method for the determination of vanadium at nanotrace levels in some environmental, biological, soil, food, and pharmaceutical samples using salicylaldehyde-benzoylhydrazone

2020 ◽  
Vol 11 (4) ◽  
pp. 385-395
Author(s):  
Shaifa Abrarin ◽  
Mohammed Jamaluddin Ahmed
Keyword(s):  
Spectrophotometric Method ◽  
Biological Fluids ◽  
Stoichiometric Composition ◽  
Standard Reference Materials ◽  
Complexing Agents ◽  
Environmental Waters ◽  
Pharmaceutical Samples ◽  
Highly Sensitive ◽  
Interference Study

A very simple, non-extractive and new spectrophotometric method for the swift determination of trace amount of vanadium using salicylaldehyde-benzoylhydrazone (Sal-BH) has been developed. Sal-BH undergoes a reaction in a slightly acidic solution (0.0016-0.0032 M H2S04) with vanadium to give a light greenish-yellow chelate, which has an absorption maximum at 392 nm. The reaction is instantaneous and absorbance remains stable for over 24 hrs. The average molar absorption co-efficient and Sandell’s sensitivity were found to be 2.5039×105 L/mol.cm and 1.0 ng/cm2 V, respectively. Beer’s law was obeyed for 0.001-30 mg/L of V, providing a detection limit of 0.1 µg/L of V and RSD 0-2 %. The stoichiometric composition of the chelate is 1:1 (V:Sal-BH). Interference study shows that a large excess of over 60 cations, anions, and some common complexing agents (such as chloride, azide, tartrate, EDTA and SCN‑, etc.) satisfy the tolerance limit. The developed method was successfully used in the determination of vanadium in several standard reference materials as well as in some environmental waters, biological fluids, soil, food and pharmaceutical samples and solutions containing both vanadium (IV) and vanadium (V). The results of the proposed method for assessing biological, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg/L).

scholarly journals Determination of Urinary Gluten Immunogenic Peptides to Assess Adherence to the Gluten-Free Diet: A Randomized, Double-Blind, Controlled Study

2021 ◽  
Vol 12 (10) ◽  
pp. e00411
Author(s):  
Chiara Monachesi ◽  
Anil K. Verma ◽  
Giulia N. Catassi ◽  
Elisa Franceschini ◽  
Simona Gatti ◽  
...  
Keyword(s):  
Gluten Free Diet ◽  
Controlled Study ◽  
Gluten Free ◽  
Double Blind ◽  
Immunogenic Peptides

Methods for the Determination of the Purity of Exosomes

2020 ◽  
Vol 25 (42) ◽  
pp. 4464-4485 ◽  
Author(s):  
Katarzyna Kluszczyńska ◽  
Liliana Czernek ◽  
Wojciech Cypryk ◽  
Łukasz Pęczek ◽  
Markus Düchler
Keyword(s):  
Drug Transport ◽  
Biological Fluids ◽  
Drug Carriers ◽  
Biological Functions ◽  
Isolation And Purification ◽  
Pubmed Database ◽  
High Concentrations ◽  
Targeted Release

Background: Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance. Methods: Articles describing the isolation and purification of exosomes were retrieved from the PubMed database. Results: Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols. Conclusion: Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

Microextraction and Chromatographic Analysis of Budesonide Epimers in Exhaled Breath Condensate

2020 ◽  
Vol 16 (8) ◽  
pp. 1032-1040
Author(s):  
Laleh Samini ◽  
Maryam Khoubnasabjafari ◽  
Mohamad M. Alimorad ◽  
Vahid Jouyban-Gharamaleki ◽  
Hak-Kim Chan ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Exhaled Breath Condensate ◽  
Low Cost ◽  
Exhaled Breath ◽  
Chromatography Method ◽  
Extraction Solvent ◽  
Drug Concentrations ◽  
Dispersive Liquid Liquid Microextraction ◽  
Breath Condensate

Background: Analysis of drug concentrations in biological fluids is required in clinical sciences for various purposes. Among other biological samples, exhaled breath condensate (EBC) is a potential sample for follow up of drug concentrations. Methods: A dispersive liquid-liquid microextraction (DLLME) procedure followed by a validated liquid chromatography method was employed for the determination of budesonide (BDS) in EBC samples collected using a homemade setup. EBC is a non-invasive biological sample with possible applications for monitoring drug concentrations. The proposed analytical method is validated according to the FDA guidelines using EBC-spiked samples. Its applicability is tested on EBC samples collected from healthy volunteers receiving a single puff of BDS. Results: The best DLLME conditions involved the use of methanol (1 mL) as a disperser solvent, chloroform (200 μL) as an extraction solvent, and centrifugation rate of 3500 rpm for 5 minutes. The method was validated over a concentration range of 21-210 μg·L-1 in EBC. Inter- and intra-day precisions were less than 10% where the acceptable levels are less than 20%. The validated method was successfully applied for the determination of BDS in EBC samples. Conclusion: The findings of this study indicate that the developed method can be used for the extraction and quantification of BDS in EBC samples using a low cost method.

A Review of Analytical Methods for the Determination of Tibolone: Pharmacokinetics and Pharmaceutical Formulations Analysis and Application in Doping Control

2020 ◽  
Vol 17 (1) ◽  
pp. 31-39
Author(s):  
Marilene Lopes Ângelo ◽  
Fernanda de Lima Moreira ◽  
Ana Laura Araújo Santos ◽  
Hérida Regina Nunes Salgado ◽  
Magali Benjamim de Araújo
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Analytical Methods ◽  
Estrogenic Activity ◽  
Biological Fluids ◽  
Pharmaceutical Formulations ◽  
Doping Control ◽  
Specific Effects ◽  
In Doping

Background:: Tibolone is a synthetic steroid commercialized by Organon under the brand name Livial (Org OD14), which is used in hormone therapy for menopause management and treatment of postmenopausal osteoporosis. Tibolone is defined as a selective tissue estrogenic activity regulator (STEAR) demonstrating tissue-specific effects on several organs such as brain, breast, urogenital tract, endometrium, bone and cardiovascular system. Aims:: This work aims to (1) present an overview of important published literature on existing methods for the analysis of tibolone and/or its metabolites in pharmaceutical formulations and biological fluids and (2) to conduct a critical comparison of the analytical methods used in doping control, pharmacokinetics and pharmaceutical formulations analysis of tibolone and its metabolites. Results and conclusions: : The major analytical method described for the analysis of tibolone in pharmaceutical formulations is High Pressure Liquid Chromatography (HPLC) coupled with ultraviolet (UV) detection, while Liquid Chromatography (LC) or Gas Chromatography (GC) used in combination with Mass Spectrometry (MS) or tandem mass spectrometry (MS/MS) is employed for the analysis of tibolone and/or its metabolites in biological fluids.

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