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BioMed Research International 2021Elderly patients receiving nasal feeding have weaker physiological function, and placement of a nasogastric tube weakens the natural barrier of the cardia-esophageal...
BACKGROUND
Elderly patients receiving nasal feeding have weaker physiological function, and placement of a nasogastric tube weakens the natural barrier of the cardia-esophageal sphincter; therefore, the risk of gastroesophageal reflux (GER) is higher. Many studies have shown that pepsin is extremely sensitive in predicting GERD, so this study intends to investigate the level of pepsin in saliva of elderly patients with nasal feeding and analyze its influencing factors.
METHODS
This was a cross-sectional study. Patients admitted to the Chinese PLA General Hospital from April 2018 to October 2018 who received nasal feeding were included. One ml of saliva was collected from each patient in while sitting during fasting in the morning and 1 hour after lunch for 3 consecutive days. Pepsin was quantified by enzyme-linked immunosorbent assay (ELISA). The patients were predivided into two groups (≥7.75g/ml or <7.75g/ml) based on the median pepsin. Baseline and clinical factors were compared.
RESULTS
The mean age of the patients was 91.09 ± 4.91 years. There were statistical differences in diabetes and feeding methods between the two groups. There was a positive correlation between the morning and postprandial pepsin levels ( = 0.442, < 0.001), and has no statistical difference ( = 0.175). Multivariate analysis showed that the risk factors for higher pepsin levels were diabetes (odds ratio (OR): 2.67; 95% CI: 1.225-5.819, = 0.013) and nasal feeding methods (OR: 2.475; 95% CI: 1.183-5.180, =0.016).
CONCLUSIONS
For patients undergoing nasal feeding who are older than 80 years, the fasting and 1-hour postprandial pepsin concentration were consistent. Diabetes and feeding methods are risk factors for high pepsin levels. For the elderly over 80 years old, age has no influence on pepsin concentration.
Topics: Administration, Intranasal; Aged; Aged, 80 and over; Eating; Electric Impedance; Esophageal pH Monitoring; Esophagus; Feeding Methods; Female; Gastroesophageal Reflux; Humans; Male; Pepsin A; Saliva
PubMed: 33564676
DOI: 10.1155/2021/4721812 -
Analytical Chemistry Dec 2023Salivary pepsin has been proposed as a promising diagnostic marker for gastroesophageal reflux disease (GERD). However, the activity of human pepsin is strongly...
Salivary pepsin has been proposed as a promising diagnostic marker for gastroesophageal reflux disease (GERD). However, the activity of human pepsin is strongly influenced by pH, and the acidic condition (pH ∼ 2) is optimal, which is a contradiction for the pepsin detection kit based on its catalytic activity. Thus, its accurate quantification in saliva (neutral pH) by readily rapid tools with simplicity and low cost is still challenging. Herein, a convenient fluorescence assay has been developed for the rapid detection of pepsin at neutral pH based on its electrostatic interaction with SYBR Green (SG) rather than the bioactivity. At neutral pH, the positively charged SG fluorophore can be effectively adsorbed by the negatively charged pepsin due to the low isoelectric point (pI) and large molecular size of pepsin. Thus, the molecular rotation of SG is limited, and its fluorescence intensity is significantly increased. The strategy was further confirmed to have the same fluorescence response as that of normally active and inactivated pepsin. Due to the unique pI of pepsin, the fluorescence strategy is highly selective for pepsin compared to other proteins. On the basis of this strategy, a smartphone-based fluorescence capture device integrated with a programmed Python program was fabricated for both color recognition and the accurate detection of pepsin within 3 min. Under the optimal conditions, this turn-on sensor allowed for the on-site analysis of pepsin with a detection limit of 0.2 μg/mL. Moreover, this strategy was successfully used to assess salivary pepsin to aid in the noninvasive diagnosis of GERD.
Topics: Humans; Saliva; Pepsin A; Static Electricity; Gastroesophageal Reflux; Hydrogen-Ion Concentration
PubMed: 38019658
DOI: 10.1021/acs.analchem.3c04723 -
BMC Gastroenterology Nov 2017Functional dyspepsia (FD) is a gastrointestinal disorder characterized by recurrent and diverse symptoms and pathophysiology that remains unexplained following routine... (Observational Study)
Observational Study
BACKGROUND
Functional dyspepsia (FD) is a gastrointestinal disorder characterized by recurrent and diverse symptoms and pathophysiology that remains unexplained following routine clinical investigation. Enzynorm®f is a pharmaceutical preparation comprising fixed amounts of pepsin of biological origin and organically bound acid in the form of amino acid hydrochloride. It is traditionally used as a mild agent to support gastric function and to stimulate the stomach's proteolytic activities in FD.
METHODS
In a non-interventional, observational, post-marketing surveillance study, patients with an established diagnosis of FD were treated with a fixed combination of pepsin and amino acid hydrochloride taken as tablets three times daily for 6 weeks. The primary objective of this study was to assess the change in symptoms using the validated Gastrointestinal Symptom Score (GIS©). Secondary objectives included patients' assessment of their gastrointestinal symptoms as well as treatment safety and tolerability.
RESULTS
A total of 97 patients (mean age 58.4 ± 13.9 years; 63.2% females) were included in the study, with 72 data having GIS© score data at baseline and at 6 weeks, and 34 also at 3 weeks. The overall GIS© sum score decreased by 4.1 (p < 0.0001) from 11.6 (±4.8) at baseline to 7.4 (± 4.6) reflecting an improvement of clinical symptomatology after 6 weeks of treatment. In a subgroup of 70 patients who had FD meeting the Rome III criteria a GIS© score reduction of ≥50% was observed after 3 weeks treatment in 24% and in 30.8% after 6 weeks. Adverse events were mostly gastrointestinal in nature and consistent with the underlying disease; no unexpected adverse reactions were reported. Twenty-seven patients discontinued the study, mostly because of gastrointestinal symptoms.
CONCLUSION
The results of this study support the efficacy of a fixed combination of pepsin and amino acid hydrochloride for the treatment of patients with FD and also suggest good to moderate treatment tolerability. These findings should be further explored in a randomised, placebo-controlled clinical trial.
CLINICAL TRIAL REGISTRATION
This study has been retrospectively registered in the ClinicalTrials.gov registry, trial identifier NCT03076411 .
Topics: Amino Acids; Drug Administration Schedule; Drug Combinations; Dyspepsia; Female; Gastrointestinal Agents; Humans; Male; Middle Aged; Patient Outcome Assessment; Pepsin A; Product Surveillance, Postmarketing; Treatment Outcome
PubMed: 29178842
DOI: 10.1186/s12876-017-0675-9 -
The Laryngoscope Jan 2020Idiopathic subglottic stenosis (iSGS) is commonly characterized by laryngeal fibrosis thought to arise by epithelia-mesenchymal transition (EMT) induced by chronic...
OBJECTIVES
Idiopathic subglottic stenosis (iSGS) is commonly characterized by laryngeal fibrosis thought to arise by epithelia-mesenchymal transition (EMT) induced by chronic inflammation. Pepsin is a potent inducer of inflammation in the airways during chronic laryngopharyngeal reflux and has been observed in the subglottic mucosa of patients with iSGS, absent in normal mucosa. The aim of this study was to examine the effect of pepsin on mechanisms of EMT in laryngeal cells with implications for iSGS.
STUDY DESIGN
In vitro translational research study.
METHODS
Human laryngeal epithelial cell cultures were exposed to 0.1 mg/mL or 1.0 mg/mL pepsin at pH7 for 24 and 48 hours, or media pH5 ± 0.1 mg/mL pepsin for 10 minutes and harvested after 24 and 48 hours. EMT marker expression was measured by qPCR and enzyme-linked immunosorbent assays. Wound-healing scratch assay was performed on immortalized human vocal fold fibroblasts pretreated with media pH5 ± 0.1 mg/mL pepsin (10 minutes) or continuously treated with media pH7 ± 0.1 to 1 mg/mL pepsin for 24 hours.
RESULTS
Pepsin yielded no effect on MMP1, MMP9, FN1, COL1A1, HAS2, or CDH1 gene expression or matrix metalloproteinase-9 or fibronectin protein expression, either alone or in the presence of weak acid. Pepsin and/or acid produced no effect on fibroblast migration.
CONCLUSION
Whereas pepsin has been shown to be present in the subglottic mucosa of patients with iSGS, this in vitro acute exposure investigation does not provide evidence of a direct causal role for development of fibrosis in subglottic epithelial cell cultures.
LEVELS OF EVIDENCE
NA. Laryngoscope, 130:154-158, 2020.
Topics: Cells, Cultured; Epithelial Cells; Epithelial-Mesenchymal Transition; Humans; Laryngostenosis; Larynx; Pepsin A
PubMed: 30776094
DOI: 10.1002/lary.27879 -
Enzyme and Microbial Technology Oct 2021The present study sought to identify the structural determinants of aspartic protease structural stability and activity at elevated pH. Various hypotheses have been...
The present study sought to identify the structural determinants of aspartic protease structural stability and activity at elevated pH. Various hypotheses have been published regarding the features responsible for the unusual alkaline structural stability of renin, however, few structure-function studies have verified these claims. Using pepsin as a model system, and renin as a template for functional and structural alkaline stability, a rational re-design of pepsin was undertaken to identify residues contributing to the alkaline instability of pepsin-like aspartic proteases in regards to both structure and function. We constructed 13 mutants based on this strategy. Among them, mutants D159 L and D60A led to an increase in activity at elevated pH levels (p ≤ 0.05) and E4V and H53F were shown to retain native-like structure at elevated pH (p ≤ 0.05). Previously suggested carboxyl groups Asp, Asp, and Glu were individually shown not to be responsible for the structural instability or lack of activity at neutral pH in pepsin. The importance of the β-barrel to structural stability was highlighted as the majority of the stabilizing residues identified, and 39% of the weakly conserved residues in the N-terminal lobe, were located in β-sheet strands of the barrel. The results of the present study indicate that alkaline stabilization of pepsin will require reduction of electrostatic repulsions and an improved understanding of the role of the hydrogen bonding network of the characteristic β-barrel.
Topics: Amino Acid Sequence; Aspartic Acid Endopeptidases; Hydrogen Bonding; Pepsin A; Renin
PubMed: 34489030
DOI: 10.1016/j.enzmictec.2021.109871 -
American Journal of Otolaryngology 2020This study aimed to evaluate if laryngopharyngeal reflux (LPR) plays a role as a risk factor for vocal fold polyps (VFPs), and if pepsin is associated with higher...
PURPOSE
This study aimed to evaluate if laryngopharyngeal reflux (LPR) plays a role as a risk factor for vocal fold polyps (VFPs), and if pepsin is associated with higher oxidative DNA damage of VFPs in the presence of LPR.
METHODS
Thirty patients with VFPs were recruited between 2017 and 2018. Prior to surgery, a laryngoscopy was performed on all subjects to evaluate VFPs. Polyp tissue and saliva samples were obtained scrupulously. Hematoxylin-eosin staining was performed for pathologic analysis. Immunohistochemistry and ELISA were used to detect pepsin in tissue and saliva of VFP patients. 8-OHdG and p-H2AX expression was detected to measure oxidative DNA damage in tissue. DNA damage was investigated in human immortalized laryngeal epithelial cells exposed to pepsin.
RESULTS
The pepsin concentration in saliva was significantly higher (t = 2.38, P = .024) in the pepsin positive group. There was no significant difference in pepsin expression at different sites and pathological subtypes of VFPs. The levels of 8-OHdG and p-H2AX were significantly higher in the pepsin positive group and positively correlated with the tissue expression of pepsin. The concentration of pepsin in saliva also showed a significant correlation with 8-OHdG levels. Expression of 8-OHdG and p-H2AX, and tail moment of the comet assay were elevated in human immortalized laryngeal epithelial cells following treatment with pepsin.
CONCLUSION
Patients with VFPs have higher levels of oxidative DNA damage in the presence of pepsin reflux. Pepsin may induce DNA damage in laryngeal epithelial cells and participate in the pathogenesis of VFPs.
Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Female; Gene Expression; Histones; Humans; Laryngeal Diseases; Laryngopharyngeal Reflux; Male; Oxidative Stress; Pepsin A; Polyps; Vocal Cords
PubMed: 32889371
DOI: 10.1016/j.amjoto.2020.102681 -
Methods in Cell Biology 2023Celiac disease (CD) is an intestinal autoimmune disorder developed in genetically susceptible individuals upon gluten ingestion. Gliadin is known to be the most...
Celiac disease (CD) is an intestinal autoimmune disorder developed in genetically susceptible individuals upon gluten ingestion. Gliadin is known to be the most immunogenic gluten component, which can activate the host immune response represented by NFkB activation and release of proinflammatory cytokines as IL8. However, many aspects of the involvement of gliadin in CD pathophysiology is not well understood yet. Lack of a CD animal model increases difficulty elucidating key steps in CD development, what increases the importance of in vitro experiments. Here we present a protocol for in vitro pepsin-trypsin digested gliadin (PTG) treatment for long term studies in HCT116 intestinal cell line.
Topics: Animals; Gliadin; Pepsin A; Trypsin; Intestines; Glutens
PubMed: 37625867
DOI: 10.1016/bs.mcb.2022.11.002 -
Spectrochimica Acta. Part A, Molecular... Jan 2024Vildagliptin (VDG) and Metformin (Met) belong to a class of dipeptidylpeptidase-4 (DPP-4) inhibitor and biguanide, respectively and used for the management of diabetes...
Vildagliptin (VDG) and Metformin (Met) belong to a class of dipeptidylpeptidase-4 (DPP-4) inhibitor and biguanide, respectively and used for the management of diabetes mellitus type II (DMTII). Both the drugs are orally available which leads to various side effects due to its oral ingestion. Occurrence of these side effects might be due to some interactions with pepsin at a molecular level. Therefore, in order to investigate these interactions, multi-spectroscopic and in-silico techniques have been extensively studied to identify the binding characteristics of VDG with pepsin. Fluorescence data suggested that the quenching is due to dynamic and static mechanism and static was dominant one. However, fluorescence and UV-Vis spectroscopic measurement analysis suggested that VDG tends to associate with pepsin, via ground-state complex formation. Fluorescence study revealed the binding-constant value which was found to be 0.559 × 10 M at 298.15 K that is non-covalent in nature. VDG-pepsin complex shows exothermic and spontaneous binding as confirmed by the calculated values of ΔH, ΔS, and ΔG, are majorly caused by van der Waals forces and H-bonding interactions. CD spectra of pepsin in presence of VDG confirmed post binding conformational change. Enzyme-activity assay showed that activity of pepsin was decreased by upto 28 %. FRET analysis suggested that energy transfer efficiency is negligible for VDG-pepsin interaction. In-silico analysis reveals that H-bonding and electrostatic negative forces are the significant driving forces involved in the interaction of VDG and pepsin.
Topics: Spectrometry, Fluorescence; Binding Sites; Pepsin A; Vildagliptin; Metformin; Molecular Docking Simulation; Protein Binding; Thermodynamics; Circular Dichroism
PubMed: 37748335
DOI: 10.1016/j.saa.2023.123368 -
Spectrochimica Acta. Part A, Molecular... Apr 2020In this work, the effects of I on the activities and conformational structures of digestive enzymes, trypsin and pepsin were studied. The results indicated that the...
In this work, the effects of I on the activities and conformational structures of digestive enzymes, trypsin and pepsin were studied. The results indicated that the enzyme activities were decreased to some extent in the presence of I, especially trypsin. Upon gradual addition of I, the intrinsic fluorescence quenching of trypsin and pepsin were observed by mainly static collision and hydrophobic forces. I is more likely to cause the fluorescence quenching of trypsin than that of pepsin. Compared with pepsin, trypsin has a greater ability to bind with I. The synchronous fluorescence spectral results indicated that I induced the quaternary structure changes of trypsin/pepsin and changed the hydrophobicity of Tyr and Trp residues. In addition, molecular docking was used to obtain the binding mode and the various amino acid residues of trypsin and pepsin with I. These investigations may constitute a solid work to further explain the process of migration and transformation of I in digestive system.
Topics: Animals; Iodine; Molecular Docking Simulation; Pepsin A; Protease Inhibitors; Protein Binding; Protein Structure, Quaternary; Swine; Trypsin; Trypsin Inhibitors
PubMed: 31931358
DOI: 10.1016/j.saa.2020.118036 -
Medical Science Monitor : International... Dec 2018BACKGROUND Gastroesophageal reflux disease (GERD) is very common. Salivary pepsin detection has previously been considered as a method for GERD diagnosis. We performed a... (Meta-Analysis)
Meta-Analysis
BACKGROUND Gastroesophageal reflux disease (GERD) is very common. Salivary pepsin detection has previously been considered as a method for GERD diagnosis. We performed a meta-analysis to investigate the utility of salivary pepsin assay as a diagnostic tool of GERD. MATERIAL AND METHODS PubMed, Web of Science, the Cochran Library, and EMBASE (from January 1980 to 23 October 2018) were searched for pepsin in saliva for GERD diagnosis. We summarized the retrieved specificity, sensitivity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), diagnostic odds ratio (DOR), and receiver operating characteristic (ROC) curves data in the meta-analysis. RESULTS In final analysis, a total of 5 studies were included. The summary sensitivity, specificity, NLR, and PLR were 0.60 (95% CI 0.41-0.76), 0.71 (95% CI 0.51-0.86), 0.56 (95% CI 0.34-0.93), and 2.1 (95% CI 1.1-4.1), respectively. The pooled DOR was 4 (95% CI 1.0-11.0) and area under the ROC was 0.70 (95% CI 0.66-0.74). CONCLUSIONS The meta-analysis showed that pepsin in saliva has moderate diagnostic value for GERD, and is not as helpful as previously thought.
Topics: Adult; Biomarkers; Gastroesophageal Reflux; Humans; Odds Ratio; Pepsin A; ROC Curve; Saliva; Sensitivity and Specificity
PubMed: 30596632
DOI: 10.12659/MSM.913978